This week, I have a three pack of prospects who have been tearing it up for the Fisher Cats. One is a top prospect, another a fringe future utility man, and the third a former high draft selection who might just have some embers glowing among the ashes of his prospect status.
Sem Robberse, 21, RHP, AA New Hampshire
Robberse went 6 innings on Saturday, striking out 7 with just one hit and one walk. It was his best start of the season, but also his third time striking out 7 or more in six tries this season, after accomplishing the feat just eight times in the past two seasons combined. His 25% K rate ties his career high from back in A ball.
As Matt noted in his top 40 write-up, Robberse uses solid command to make the most of stuff that’s just solid. He’s lacked a clear plus pitch in the past (though his change up has shown flashes), leading to some risk that he wouldn’t be able to put major leaguers. This spring, however, he showed up with some additional muscle and throwing 92-94 in short outings, as opposed to his previous 91. We don’t have StatCast for Eastern League games, so I can’t tell whether that velocity bump has translated into full starts in the regular season. What I can say, though, is that his 15.1% swinging strike rate is a career best at any level, by about 2 percentage points, suggesting that something has changed.
It hasn’t been a smooth road. the Dutchman has also had a couple of blow up outings in which he’s yielded four runs in four innings, so his overall 3.64 ERA and 4.37 FIP aren’t sterling. If he can harness his newfound bat missing ability to his usual plus command more consistently, though, the ingredients are here for a breakout.
Adam Kloffenstein, 22, RHP, AA New Hampshire
The 2018 third round pick fell entirely off our top 40 this year after two years of struggles. This year, though, finally, there are some signs of improvement. His six shutout innings on Friday, in which he scattered 7 hits without issuing a walk and struck out 8, were the best outing yet in what has been a surprisingly solid first six starts. His 30% strikeout rate is a career best, and his 2.52 ERA and 2.66 FIP are by far his best marks since low A back in 2019.
Statistically, there’s no one clear indicator that explains the change, but a couple of things have taken small steps forward. His swinging strike rate is up slightly from last year, 15.5% vs 14.5%. He’s throwing more strikes, a career high 64% vs 61%. He’s also recovered his strong ground ball ability, keeping 57% of opponent contact on the ground after it dropped to 40% last season.
When Kloffenstein signed out of high school back in 2018, he was still just 17 years old. He’s been in the system for so long that it’s easy to forge that he’s still only 22, age appropriate for AA as a prospect. It’ll take more than a solid month to erase two years of 6 ERAs and stalled development, but for the first time in a few years there are glimmers of hope.
Steward Berroa, 23, Switch OF, AA New Hampshire
Berroa made my pref list this past off-season on the strength of his elite speed. That’s been on display this season, as he’s already stolen 9 bases on a dozen attempts. Surprisingly, though, he’s also excelled at the plate. This past week, he went 5 for 13 with two doubles and a home run, striking out and walking 4 times each. That brought his season line to .275/.400/.493, 49% better than the Eastern League average.
The improvement is across the board. His strikeout rate (22.4%) is down 4 percentage points from last year, powered by an 8.1% swinging strike rate that’s 2 percentage points better than his mark in High A last year and a career best above rookie ball and puts him just outside the top 10 among Eastern League regulars. He’s also kicked his usually excellent walk rate into overdrive, taking free passes 17.6% of the time.
Lastly, his isolated power (.217) is a career best, and his 3 home runs are almost half way to matching his total from each of the past two years (7) in about a quarter of the PAs. Part of that is likely due to the lefty friendly confines of Northeast Delta Dental Stadium, which is just 306 feet to the corner and 353 to the power alley in right. All three homers have come at home. He also has six doubles, though, which again puts him on track to surpass last season’s extra base hit total.
As I said in my list, Berroa doesn’t need to hit a lot to carve out a major league role. Just getting to tolerable is enough to allow his speed to play in the field and on the base paths. Everything he’s done this season makes that outcome a little more likely.