Jonatan Clase

Organization Prospect Rankings

• 
  Ranked Seattle Mariners #10 prospect in 2024
  BA Grade: 50/High
  
  Track Record: The Mariners signed Clase for $35,000 out of the Dominican Republic in 2018 and quickly realized they had a potential steal. Injuries and the coronavirus pandemic limited him to 70 games combined in his first three seasons, but he broke out at Low-A Modesto in 2022 and continued his ascent in 2023. Clase hit a career-high 20 home runs, finished third in the minors with 79 steals and earned a selection to the Futures Game as he climbed to Double-A Arkansas. He also struck out 165 times, second-most in the Mariners system, and hit .222/.331/.396 in 108 games at Double-A.
  
  Scouting Report: Clase has prolific tools but is learning to translate them into skills. He has plus-plus speed, plus raw power from both sides of the plate and the athleticism to be an above-average defender in center field. Clase’s tools are evident, but he is a wild swinger with poor instincts in every facet of the game. He has poor barrel accuracy and chases pitches he can’t hit. He tries to do too much at the plate and needs to tone down his aggressiveness to be even a well below-average hitter. Despite his raw power, Clase doesn’t project to make enough contact to hit more than 10-15 home runs per season. Clase’s speed allows him to outrun bad jumps and indirect routes on the basepaths and in the outfield. He is an aggressive and energetic player, who alternately excites and frustrates.
  
  The Future: Clase has to mature as a player to fulfill his potential as a bottom-of-the-order, speed-driven center fielder. That will be his main goal in 2024.
  
  Scouting Grades Hit: 30 | Power: 45 | Run: 70 | Field: 55 | Arm: 50
• 
  Ranked Seattle Mariners #12 prospect in 2023
  BA Grade/Risk: 50/Very High
  
  Track Record: Clase signed with the Mariners for $35,000 in 2018 and quickly showed some of the most prolific tools in the system. The coronavirus pandemic and repeated hamstring and quad strains limited him to just 70 games in his first three years as a professional, but he stayed healthy in 2022 and put together a productive season at Low-A Modesto. He led the California League with 11 triples and 55 stolen bases and showed exciting power-speed potential, but he also showed a concerning lack of plate discipline.
  
  Scouting Report: Clase is the fastest and most electric player in the Mariners system by a fair margin. He is a strong, twitchy athlete with plus-plus speed and can change games with both his power and his legs. He is a switch-hitter who can drive the ball from both sides of the plate and has grown into plus raw power, particularly from the left side. Clase's speed and strength are tantalizing, but he's a wild free swinger who takes big hacks and lacks instincts in the batter's box. He struggles with changing speeds and doesn't make adjustments, limiting him to a well below-average hitter. Clase's speed makes him a threat on the bases even when he gets bad jumps. He covers wide swaths of ground in center field and projects to be an above-average defender with an average arm.
  
  The Future: Clase has the tools to be an everyday center fielder, but he will have to improve his approach against higher-level pitching to get there. He'll begin 2023 at High-A Everett.
  
  Scouting Grades: Hit: 30. Power: 50. Speed: 70. Fielding: 55. Arm: 50.
• 
  Ranked Seattle Mariners #26 prospect in 2022
  Track Record: Clase signed with the Mariners for $35,000 during the 2018 international signing period and quickly emerged as a potential steal. He hit .300 with 21 extra-base hits and 31 stolen bases in his pro debut in the Dominican Summer League, but injuries have sidetracked his development. Clase suffered repeated hamstring and quad strains over the last two years and played only 14 games in the Arizona Complex League in 2021.
  
  Scouting Report: Clase is a nearly 80-grade runner who gets to top speed quickly and wreaks havoc on the basepaths. He uses his speed to cover wide swaths of ground in center field and has good instincts for the position, helping him project to be at least an above-average defender with an average arm. Clase has excellent strike-zone awareness and began switch-hitting in 2021 after previously batting only lefthanded. He is naturally righthanded and shows the potential to be an average hitter from both sides. He has added strength since signing, but power is not his game. Clase’s main challenge is staying healthy. He has played only 77 games in three years and has missed a lot of crucial development time.
  
  The Future: Clase needs to show he can stay on the field. If he can, his speed, defense and switch-hitting ability make him a potential breakout candidate.
  
• 
  Ranked Seattle Mariners #30 prospect in 2021
  TRACK RECORD: Clase signed with the Mariners for $35,000 in 2018 and delivered an intriguing pro debut in the Dominican Summer League the following year. He was set to make his stateside debut in 2020 before the coronavirus pandemic canceled the minor league season. He got back on the field for instructional league in the fall.
  
  SCOUTING REPORT: Clase has packed on 30 pounds of muscle since signing, giving him a brick-like build. Impressively, he's maintained his plus-plus speed as he's added the weight. Clase has a slasher's approach in games with excellent bat speed and controls the strike zone. His approach and swing aren't conducive to hitting for power, so he'll need to make adjustments to get the most from his newfound strength. Namely, he needs to get better at learning which pitches he can impact. Clase relies on his natural speed and athleticism in the outfield but needs to improve his routes. He may project better as a corner outfielder even with his speed.
  
  THE FUTURE: Clase has strength and athleticism to dream on, but he's still very raw. He'll be 18 on Opening Day 2021 and will begin in the Rookie-level Arizona League.
• 
  Ranked Seattle Mariners #26 prospect in 2020
  TRACK RECORD: Signed for just $35,000 in 2018, Clase surprised with a strong first pro season in the Dominican Republic when he posted a batting line of .300/.434/.444 with 31 stolen bases. He was extremely raw when he first came to the Mariners' academy in the DR but has made big strides through hard work. Clase has already added 30 pounds to his athletic frame by spending significant time in the weight room.
  
  SCOUTING REPORT: Clase's defining tool is his plus-plus speed, graded as a 70 runner on the 20-80 scouting scale. He uses a short, compact swing, making contact with sneaky power for his size. Clase's 18 percent walk rate is impressive for a player so unrefined. Currently he shows more range than feel in the outfield, with some of the routes he takes being called “adventurous,” but he has the closing speed to get to balls and will improve his routes with more experience.
  
  THE FUTURE: Clase will make his stateside debut in 2020 with an assignment to the Rookie-level Arizona League after time in extended spring training. He's an intriguing talent.

• February, 2023 Scouting Report
  BA Grade/Risk: 50/Very High
  
  Track Record: Clase signed with the Mariners for $35,000 in 2018 and quickly showed some of the most prolific tools in the system. The coronavirus pandemic and repeated hamstring and quad strains limited him to just 70 games in his first three years as a professional, but he stayed healthy in 2022 and put together a productive season at Low-A Modesto. He led the California League with 11 triples and 55 stolen bases and showed exciting power-speed potential, but he also showed a concerning lack of plate discipline.
  
  Scouting Report: Clase is the fastest and most electric player in the Mariners system by a fair margin. He is a strong, twitchy athlete with plus-plus speed and can change games with both his power and his legs. He is a switch-hitter who can drive the ball from both sides of the plate and has grown into plus raw power, particularly from the left side. Clase's speed and strength are tantalizing, but he's a wild free swinger who takes big hacks and lacks instincts in the batter's box. He struggles with changing speeds and doesn't make adjustments, limiting him to a well below-average hitter. Clase's speed makes him a threat on the bases even when he gets bad jumps. He covers wide swaths of ground in center field and projects to be an above-average defender with an average arm.
  
  The Future: Clase has the tools to be an everyday center fielder, but he will have to improve his approach against higher-level pitching to get there. He'll begin 2023 at High-A Everett.
  
  Scouting Grades: Hit: 30. Power: 50. Speed: 70. Fielding: 55. Arm: 50.
• December, 2022 Scouting Report
  BA Grade/Risk: 50/Very High
  
  Track Record: Clase signed with the Mariners for $35,000 in 2018 and quickly showed some of the most prolific tools in the system. The coronavirus pandemic and repeated hamstring and quad strains limited him to just 70 games in his first three years as a professional, but he stayed healthy in 2022 and put together a productive season at Low-A Modesto. He led the California League with 11 triples and 55 stolen bases and showed exciting power-speed potential, but he also showed a concerning lack of plate discipline.
  
  Scouting Report: Clase is the fastest and most electric player in the Mariners system by a fair margin. He is a strong, twitchy athlete with plus-plus speed and can change games with both his power and his legs. He is a switch-hitter who can drive the ball from both sides of the plate and has grown into plus raw power, particularly from the left side. Clase's speed and strength are tantalizing, but he's a wild free swinger who takes big hacks and lacks instincts in the batter's box. He struggles with changing speeds and doesn't make adjustments, limiting him to a well below-average hitter. Clase's speed makes him a threat on the bases even when he gets bad jumps. He covers wide swaths of ground in center field and projects to be an above-average defender with an average arm.
  
  The Future: Clase has the tools to be an everyday center fielder, but he will have to improve his approach against higher-level pitching to get there. He'll begin 2023 at High-A Everett.
  
  Scouting Grades: Hit: 30. Power: 50. Speed: 70. Fielding: 55. Arm: 50.
• April, 2022 Scouting Report
  BA Grade: 45/Very High
  
  Track Record: Clase signed with the Mariners for $35,000 during the 2018 international signing period and quickly emerged as a potential steal. He hit .300 with 21 extra-base hits and 31 stolen bases in his pro debut in the Dominican Summer League, but injuries have sidetracked his development. Clase suffered repeated hamstring and quad strains over the last two years and played only 14 games in the Arizona Complex League in 2021.
  
  Scouting Report: Clase is a nearly 80-grade runner who gets to top speed quickly and wreaks havoc on the basepaths. He uses his speed to cover wide swaths of ground in center field and has good instincts for the position, helping him project to be at least an above-average defender with an average arm. Clase has excellent strike-zone awareness and began switch-hitting in 2021 after previously batting only lefthanded. He is naturally righthanded and shows the potential to be an average hitter from both sides. He has added strength since signing, but power is not his game. Clase&#39s main challenge is staying healthy. He has played only 77 games in three years and has missed a lot of crucial development time.
  
  The Future: Clase needs to show he can stay on the field. If he can, his speed, defense and switch-hitting ability make him a potential breakout candidate.
• December, 2021 Scouting Report
  Track Record: Clase signed with the Mariners for $35,000 during the 2018 international signing period and quickly emerged as a potential steal. He hit .300 with 21 extra-base hits and 31 stolen bases in his pro debut in the Dominican Summer League, but injuries have sidetracked his development. Clase suffered repeated hamstring and quad strains over the last two years and played only 14 games in the Arizona Complex League in 2021.
  
  Scouting Report: Clase is a nearly 80-grade runner who gets to top speed quickly and wreaks havoc on the basepaths. He uses his speed to cover wide swaths of ground in center field and has good instincts for the position, helping him project to be at least an above-average defender with an average arm. Clase has excellent strike-zone awareness and began switch-hitting in 2021 after previously batting only lefthanded. He is naturally righthanded and shows the potential to be an average hitter from both sides. He has added strength since signing, but power is not his game. Clase’s main challenge is staying healthy. He has played only 77 games in three years and has missed a lot of crucial development time.
  
  The Future: Clase needs to show he can stay on the field. If he can, his speed, defense and switch-hitting ability make him a potential breakout candidate.
  
• July, 2021 Scouting Report
  TRACK RECORD: Clase signed with the Mariners for $35,000 in 2018 and delivered an intriguing pro debut in the Dominican Summer League the following year. He was set to make his stateside debut in 2020 before the coronavirus pandemic canceled the minor league season. He got back on the field for instructional league in the fall.
  
  SCOUTING REPORT: Clase has packed on 30 pounds of muscle since signing, giving him a brick-like build. Impressively, he's maintained his plus-plus speed as he's added the weight. Clase has a slasher's approach in games with excellent bat speed and controls the strike zone. His approach and swing aren't conducive to hitting for power, so he'll need to make adjustments to get the most from his newfound strength. Namely, he needs to get better at learning which pitches he can impact. Clase relies on his natural speed and athleticism in the outfield but needs to improve his routes. He may project better as a corner outfielder even with his speed.
  
  THE FUTURE: Clase has strength and athleticism to dream on, but he's still very raw. He'll be 18 on Opening Day 2021 and will begin in the Rookie-level Arizona League.
• March, 2021 Scouting Report
  TRACK RECORD: Clase signed with the Mariners for $35,000 in 2018 and delivered an intriguing pro debut in the Dominican Summer League the following year. He was set to make his stateside debut in 2020 before the coronavirus pandemic canceled the minor league season. He got back on the field for instructional league in the fall.
  
  SCOUTING REPORT: Clase has packed on 30 pounds of muscle since signing, giving him a brick-like build. Impressively, he's maintained his plus-plus speed as he's added the weight. Clase has a slasher's approach in games with excellent bat speed and controls the strike zone. His approach and swing aren't conducive to hitting for power, so he'll need to make adjustments to get the most from his newfound strength. Namely, he needs to get better at learning which pitches he can impact. Clase relies on his natural speed and athleticism in the outfield but needs to improve his routes. He may project better as a corner outfielder even with his speed.
  
  THE FUTURE: Clase has strength and athleticism to dream on, but he's still very raw. He'll be 18 on Opening Day 2021 and will begin in the Rookie-level Arizona League.
• December, 2020 Scouting Report
  TRACK RECORD: Clase signed with the Mariners for $35,000 in 2018 and delivered an intriguing pro debut in the Dominican Summer League the following year. He was set to make his stateside debut in 2020 before the coronavirus pandemic canceled the minor league season. He got back on the field for instructional league in the fall.
  
  SCOUTING REPORT: Clase has packed on 30 pounds of muscle since signing, giving him a brick-like build. Impressively, he's maintained his plus-plus speed as he's added the weight. Clase has a slasher's approach in games with excellent bat speed and controls the strike zone. His approach and swing aren't conducive to hitting for power, so he'll need to make adjustments to get the most from his newfound strength. Namely, he needs to get better at learning which pitches he can impact. Clase relies on his natural speed and athleticism in the outfield but needs to improve his routes. He may project better as a corner outfielder even with his speed.
  
  THE FUTURE: Clase has strength and athleticism to dream on, but he's still very raw. He'll be 18 on Opening Day 2021 and will begin in the Rookie-level Arizona League.
• July, 2020 Scouting Report
  TRACK RECORD: Signed for just $35,000 in 2018, Clase surprised with a strong first pro season in the Dominican Republic when he posted a batting line of .300/.434/.444 with 31 stolen bases. He was extremely raw when he first came to the Mariners’ academy in the DR but has made big strides through hard work. Clase has already added 30 pounds to his athletic frame by spending significant time in the weight room.
  
  SCOUTING REPORT: Clase’s defining tool is his plus-plus speed, graded as a 70 runner on the 20-80 scouting scale. He uses a short, compact swing, making contact with sneaky power for his size. Clase’s 18 percent walk rate is impressive for a player so unrefined. Currently he shows more range than feel in the outfield, with some of the routes he takes being called “adventurous,” but he has the closing speed to get to balls and will improve his routes with more experience.
  
  THE FUTURE: Clase will make his stateside debut in 2020 with an assignment to the Rookie-level Arizona League after time in extended spring training. He’s an intriguing talent. BA GRADE 45 Risk: High BA GRADE 40 Risk: Medium BA GRADE 50 Risk: Extreme
• February, 2020 Scouting Report
  TRACK RECORD: Signed for just $35,000 in 2018, Clase surprised with a strong first pro season in the Dominican Republic when he posted a batting line of .300/.434/.444 with 31 stolen bases. He was extremely raw when he first came to the Mariners' academy in the DR but has made big strides through hard work. Clase has already added 30 pounds to his athletic frame by spending significant time in the weight room.
  
  SCOUTING REPORT: Clase's defining tool is his plus-plus speed, graded as a 70 runner on the 20-80 scouting scale. He uses a short, compact swing, making contact with sneaky power for his size. Clase's 18 percent walk rate is impressive for a player so unrefined. Currently he shows more range than feel in the outfield, with some of the routes he takes being called “adventurous,” but he has the closing speed to get to balls and will improve his routes with more experience.
  
  THE FUTURE: Clase will make his stateside debut in 2020 with an assignment to the Rookie-level Arizona League after time in extended spring training. He's an intriguing talent.