After a successful Spring Training, what can we expect from the Mariners fastest prospect in 2024?

Back in 2018, the Mariners signed a young international player to their farm system. He was one of the smallest players taken, and wouldn't even show up on their top-30 prospects list in 2019. Not much was known about him outside of the fact that he was very fast. Nearly 6 years later, Jonatan Clase is making a name for himself in the Mariners system, and took advantage of an invite to Spring Training in 2024 to show fans he is knocking on the door of the big leagues.

It took him a while to get noticed, at least by the sites that do prospect rankings. Even in 2020, he barely cracked the top 30, ranking 29th at MLB Pipeline. They did make note that he seemed to possess top-end speed, pushing into that 80-range possibly. Also, that he had more power than you would think, adding to his strength.

Jonatan Clase is turning heads with his mix of speed, power, and defense

More came later, as he taught himself how to switch-hit, and started to do so effectively. In 2023, he would hit .246/.365/.430 as a LHB while hitting .226/.311/.513 as a RHB, even showing power from both sides of the plate. Normally, power would mean a decrease in speed. Not so for Clase, who posted a 20/70 season, just one steal short of a 20/80 season.

He got the call to Spring Training for the Mariners in 2024, and hit .321/.10/.393. It showed that he can hit well enough, but needs some work on his eye at the plate as he struck out 10 times in 28 ABs. I'm not worried about the zero walks, as he had a 13.1% BB rate at AA last season. After spending the majority of 2023 at the AA level with the Arkansas Travellers, Clase is getting close to The Show.

He turns 22 in May, and is entering that window where a strong Minor League season starts begging the question of a September call-up or injury replacement for the Mariners. It looks like he has been sent to Tacoma, which is where he is going to start the season. It's a good indicator of the Mariners trust and faith in his ability to see him head there after less than a season in AA.

For Clase to make that next leap and push for the bigs, he is going to need to keep that walk rate strong. Getting on base that often is going to be huge for someone with his game-changing speed. 13% is high, but if he can stay around double-digits, that would be a huge skill to have. The bigger issue, however, is strikeouts. We see it with many a player, but the 28% rate in AA is a bit worrisome, although not quite an unavoidable roadblock.

If Clase can keep the BB rate at 10%, keep the K rate in the 25-28% range, and find a way to push into that 240 range for batting average, you are looking at a dangerous addition to this team for someone would would be 22 to start the season in 2025. Enough pop to be dangerous, insane speed, and a great defensive weapon to put next to Julio. If things click one more time for Jonatan Clase, look out world.