The Prospect Stock Watch: Five Key Sleeper Prospects

The short-season leagues are slowing getting underway with the more advanced of those groups already playing ball. The remainder of the leagues will get going within a week. So who are some of the interesting names to know for dynasty league managers?

I’m glad you asked. Today’s piece will look at five players you should mentally file away and consider adding to your minor league rosters once they hit the full-season league (assuming you play in leagues with managers who didn’t also read this piece).

I don’t necessarily advocate taking players really early in their careers and needlessly using a roster spot on someone playing in a short-season league unless they’re extreme talents. There have only been a few players that I’ve added to my Ottoneu teams prior to their arrival in full-season ball: Vladimir Guerrero Jr., Fernando Tatis Jr., and Wander Franco.

The truth is, if you follow prospects closely, you can almost always find a good player worth adding to your roster. And adding a player too early often means you’re committing a roster spot to a player for three or four years if you grab them right out of the draft or rookie ball; more often than not in those scenarios you’ll end up ditching them before they actually help out. You’re better off leaving them unclaimed, monitoring their progress and jumping on them when the hype train starts warming up.

D’Shawn Knowles, OF, Angels

Knowles is another talented outfield prospect in an Angles’ system that also includes Jo Adell, Brandon Marsh, and Jordyn Adams. The club signed two top prospects out of the Bahamas back in July 2017 and Knowles has been the better performer to date, although he’s been returned to the advanced rookie league after spending half of 2018 at that level.

Although he hit .321 in 28 games there, it was with a .463 BABIP and 31% strikeout rate. The young outfielder doesn’t project to be much of a power hitter (although pretty much anyone can hit 20 homers these days in the MLB) and his game is really built around hitting line drives, getting on base and stealing bases. The good news is that he has a quick bat and short path to the ball so it’s really about pitch recognition and learning through repetition.

Antoni Flores, SS, Red Sox

Another 2017 signee, Flores opened 2018 in the Dominican Summer League but posted a .949 OPS and BB-K of 8-7 in 13 games before heading to Florida where he played in two games before getting hurt. The lack of experience didn’t hurt him in the Red Sox’s eyes and he was assigned to the most advanced short-season league (New York-Penn League) for the 2019 season where the 18-year-old shortstop will play against a lot of ’19 college draft picks (mostly aged 21-22).

He has a chance to hit for both power and average. He has a wide stance at the plate, which gives him good balanced, and a quiet set-up. Flores is known to use the whole field and his swing is geared to generate lift; as he continues to add good weight and muscle, more of his hits should start clearing the outfield fences.

George Valera, OF, Indians

This young outfielder jumped out to a quick start to the 2018 season before his successes were derailed by an injury just six games into his first pro season. Now 18, he’s off to another quick start with a 1.222 OPS through two games in the New York-Penn League where all three of his hits have gone for extra bases (two doubles and a homer). Valera is not the biggest guy, standing just 5-10, but he generates excellent pop due to his quick bat.

He has some noise in his set-up that might need to be toned down as he moves up to help make more consistent contact (ie. keep his bat quiet until he starts his load). He shows good patience at the plate but still needs to gain additional experience with spin so it will be important for him to play a full, healthy season this year.

Brayan Rocchio, SS, Indians

The Indians’ New York-Penn League is absolutely stacked with impressive young prospects (and Cleveland could easily have the best system in baseball in the next couple of years). Rocchio is an 18-year-old, switch-hitting shortstop with excellent bat-to-ball skills and could be ready to become one of the better prospects in baseball. He posted a 10-17 BB-K rate in 35 rookie ball games last year as at the age of 17, which is pretty impressive. He’s also an above-average runner but is still learning the nuances of base stealing after going 14-for-22 in attempts last year in rookie ball. Rocchio, like George Valera above, is not a huge guy (and has room to put on a lot of good weight/muscle) but he has a quick bat and could eventually develop some power.

Adam Kloffenstein, RHP, Blue Jays

One of the younger players available in the 2018 draft, Kloffenstein was just 17 when he signed for almost $2.5 million in the third round. Despite his youth, he’s already 6-5 and 250 pounds. He has the frame of an innings-eating fireballer but he works mostly in the low 90s right now. He also has good control for his age, can generate solid spin, and could eventually feature a four-pitch mix. He started the first game of the year for the Jays’ top short-season team in the New York-Pen League and posted a K-BB of 5-1 in three innings of work. Toronto doesn’t have much pitching depth so they’ll likely be very conservative in Kloffenstein’s development (much like they’re being with Nate Pearson) to protect his valuable arm.

Marc Hulet has been writing at FanGraphs since 2008. His work focuses on prospects and fantasy. Follow him on Twitter @marchulet.

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4 years ago

Valera has two home runs now