The Mariners’ ability to develop pitchers is well known. We’ve seen them create high-leverage bullpen arms in many situations, and they’ve elevated starters George Kirby and Logan Gilbert from strikeout pitchers to pitchers at the top of the rotation. However, lately we’ve seen them invest in some youngsters on the offensive end, like the speedy Jonatan Clase, who comes in at No. 8 in our prospect rankings.
Clase presented himself as an outfielder who used his speed to deliver hits, showcasing those skills in a spectacular debut season in 2019 (.300/.434/.878). He spent this season in the Dominican Summer League, leading the league with 31 interceptions. The 21-year-old is still probably the fastest runner in Seattle’s system, along with other top prospects. Felnin Celesten And Ryan Happiness hot on his heels.
He would spend the next few seasons working on his conditioning, which paid off in the power department, as Clase launched 32 home runs over the past two years. 2023 was a stellar campaign for the Dominican-born outfielder, as he was one of only three minor league players to hit 20 home runs (20) and steal 50 bases (79). However, the focus on power has been accompanied by a significant number of strikeouts (165 this season). Fortunately, Clase balanced swing and miss with good judgment in the strike zone, racking up 82 walks across two levels of the Mariners farm system.
20-70!?!?@Marins No. 8 prospect Jonatan Clase hit his 20th home run last night, making him the first player to post a 20-70 season in the minors since at least 1961. pic.twitter.com/kyVuHL6Ng2
– MLB Pipeline (@MLBPipeline) September 13, 2023
Clase is still perfecting his routes in center field, which he makes up for with 70 speed. Once he has the defensive side of the game locked down, the sky is the limit. We’ll see him start the 2024 season again in Arkansas as he finds the balance between contact and power to reduce strikeouts. There’s a chance to see Clase’s unique skills roam the outfielder’s grass in T-Mobile as a late-season booster.