Clint Longenecker named Amed Rosario the Appalachian League’s top prospect for Baseball America. He also placed RHP Rob Whalen at #15 in the Appy League and RHP Chris Flexen at #19.
he showed star potential in his debut season. With a lanky build, he’s an exceptional athlete with above-average speed.
“He could be a star,” a scout said. “He is 17 and can drive the ball to right-center field like a man. He has very good feel to hit and his swing generates a lot of leverage. I think he can have 20-25 home run power. I think he can be a shortstop because he has all the tools and he can run.”
Rosario makes things look easy defensively, showing good feet around the bag and the range and body control to make any play at shortstop. He has good hands and a plus arm with the ability to throw from all angles. Managers expect him to reduce his error total with experience and they say he could remain at shortstop, but he could also profile at third base as he fills out.
Rosario also drew rave reviews for his hitting ability. He has above-average bat speed with natural whip and a rare ability to drive the ball and create loud contact for his age, and he excels at hitting to the opposite field. He will need to shorten his stroke, improve on handling pitches on the inner half and polish his strike-zone discipline.
In July, when I talked to Rosario, he told me his goal was to become better at hitting the ball the other way. Perhaps the best swing I saw from him in game action was a flyball out to right where he let the ball travel deep before lifting it into an out in the opposite field. Rosario hit .241/.279/.358 in 226 PA over 58 games with a 6.6% extra-base hit rate, a 19% strikeout rate and a 4.9% walk rate. I agree, he has batspeed. The final sentence of the BA review is, ahem, extensive. I think he will have to rebuild nearly his entire swing. There’s some leg kick action but more importantly, his hand path is ugly. He dips his hands very low at the beginning creating length and a poor plane through the zone (I’ll post some video, I swear).
Mets fine-tuned his mechanics, and those tweaks, combined with a professional throwing program, helped him rediscover his stuff and finish second in the league ERA.
Whalen showed a low-90s fastball that touched 94 mph with above-average movement, and the incorporation of a sinker in addition to his four-seam fastball gave him a 2.4-to-1 groundout-to-flyout ratio. He has an advanced ability to throw strikes, and his offspeed stuff played up because of it, allowing him to use it in fastball counts. He throws a changeup, curveball and slider, and the best of the three is a high-70s curveball with three-quarters tilt that is consistently above-average.
That’s pretty far away from where I saw Whalen in July. At the time, I wrote, he “was sitting 88-89 mph with his fastball and touched 90 once or twice. He’s already listed at 6’2″ and 200 pounds, which is probably light. … He threw a few curveballs at 75-76 mph and tried a pair of changeups at 82.” I would not describe his curve as above average. Again, that’s supposed to be against MLB average.
He has an average fastball that sits in the low 90s, and his velocity could improve as he matures. He gets good downhill plane, though the pitch can lack life.
Flexen has a solid-average curveball that has improved dramatically, with good depth and late tilt. He also throws an average changeup and a slider. With command of three average or better offerings, polish and a delivery that offers deception, he should advance as a starter.
I was disappointed to miss Flexen, who I was told was touching 94, when I saw the Kingsport Mets this year.