Rintaro Sasaki has work to do to become a legitimate MLB Draft prospect

Rintaro Sasaki skipped the NPB draft to come play in the United States, enrolling at Stanford with the goal of entering the 2026 MLB draft instead. His first game experience here has come playing for the Trenton Thunder in the MLB Draft League, a very low-level summer wood-bat circuit played in the ballparks of minor-league teams contracted by MLB in 2020. I saw Sasaki on Tuesday against State College, and he’s got a long way to go to be any kind of serious prospect when he’s draft-eligible.

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Sasaki is listed at 6-feet, 230 pounds, and that might be on the low end — he’s really pretty heavy and I can’t see him playing anywhere but first base with his current build, although to his credit he moved well at first and showed a plus arm when he attempted to get a runner moving from second to third on a groundball. Most of what he did on the field looked like it was happening in slow motion, and I at least wonder if his size and conditioning are part of it.

The big problem for Sasaki now is that he couldn’t catch up to even below-average fastballs. He didn’t see a pitch over 95 on Tuesday, and in seven swings, he didn’t pull the ball or even hit it to center field once. He whiffed four times, three of them on fastballs anywhere from 91 to 95 that were in or very close to the zone, and was late on two pitches he fouled off the other way.

He had one hit in his last at bat, facing a sidearming right-hander and doubling off the left field wall towards the corner. He’s clearly very strong and this was easy power the other way, probably a homer in a typical park that doesn’t have Trenton’s high wall in left, but that was also the best possible matchup for Sasaki between the platoon advantage and the fact that he was facing a pitcher who came from a lower slot.

Rintaro Sasaki hammers it off the wall the other way to lead off the @TrentonThunder 9th pic.twitter.com/cRsjcPIfLc

— MLB Draft League (@mlbdraftleague) June 26, 2024

Sasaki is having a solid summer by performance, hitting .273/.407/.523 through 13 games with as many walks as strikeouts (9). That said, the caliber of competition in the Draft League remains very low. There wasn’t a player in this game who should go in the top five rounds, and most of the pitchers either didn’t have average velocity or couldn’t command what they did have. (Infielder Brendan Lawson, an 18-year-old commit to the University of Florida, had the night off for Trenton; he would have easily been the best prospect on the field had he played.)

It’s fine competition for a teenager trying to cut his teeth at a higher level than what he faced in high school — and that is the correct context for Sasaki, who’s been hyped to the hills as the potential No. 1 overall pick in the NPB draft and a budding superstar here. He’s a 19-year-old who has a lot of work to do just to catch up to average velocity, and who’ll probably have to work on his conditioning to be able to stay on the field. (Trust me, it doesn’t get easier as you get older.)

I am not writing Sasaki off at all, but I’m saying that he’s a long way from ready for pro ball, and he wouldn’t be a top-100 prospect in a typical draft class right now.