Name: Trevor Rosenthal
Notable 2011 Stats: 4.11 ERA, 3.04 FIP, 7 HRA, 39 BB, 133 K, 52% GB% in 120 1/3 IP with Quad Cities (A)
Why He’s This High: Rosenthal had a big year in the Midwest League to establish himself as one of the Cardinals’ top pitching prospects. A local kid from Lee’s Summit, Missouri, Rosenthal was a 21st-round pick in the 2009 draft who was mostly a reliever in short-season ball his first two seasons. In 2011, he immediately announced his presence by striking out 11 batters in four innings in his first start. His season took off from there, as he put up dominant numbers.
Given his low draft status, one might be tempted to think that Rosenthal is just a finesse guy preying on low-minors bats, but that’s not the case. He’s grown into solid velocity as a professional, and he backs up his fastball–which has reportedly touched 97 mph at times, but I wouldn’t rush to any conclusions on his velocity based on that–with a plus hard curve/slider. He throws both pitches from an easy, repeatable delivery, and he’s big enough that he should be a durable starter. He has the offspeed stuff, between the breaking ball and a solid changeup, to neutralize lefthanders, and actually had a better K/BB ratio against them (69/16) than righties (64/23).
Rosenthal demonstrated the ability to keep the ball on the ground when hitters did make contact with his good stuff, limiting homers and racking up an impressive groundball percentage. That’s a persistent trait in his statistics–he allowed just one homer in 2009 and 2010 combined, and had even higher groundball rates in those seasons. Even if his strikeout rate has some erosion against more advanced bats, Rosenthal should be able to limit the damage.
Why He’s This Low: One can’t help but be a little skeptical about a low-round pick who suddenly breaks out in the low minors, and Rosenthal’s going to have to show he can do it again to become a true upper-echelon pitching prospect.
He wore down over the course of the season, as his strikeout rate dropped from 11.05 K/9 before the All-Star Break to 8.95 K/9 after. That shouldn’t be cause for alarm–after all, he’d never pitched in a full-season league, or even started for a full short-season year. Rosenthal had thrown just 56 innings combined between 2009 and 2010, so it would be unreasonable to expect him to suddenly step in and handle 120 innings with no issues.
Rosenthal turned 21 two months into the season, so he wasn’t all that young for his level. Yes, the average age of Midwest League players was 21.7, so he was half a year younger than the average player, but this is a Top 100 Prospects list, so we’re comparing him to other top prospects, not all minor leaguers. While he was young for the level, he was fairly old for a top prospect at that level. Accordingly, he’ll need to continue to dominate hitters in order to maintain a #2 starter projection. Since his dominance consists of just 120 innings (and mainly just the first four months of 2011, since he tailed off toward the end), Rosenthal needs to continue his excellence to really cement his status.
Conclusions: Rosenthal came out of basically nowhere (the Cardinals were a weak system entering the season, and he wasn’t in Baseball America‘s Top 30 St. Louis prospects) to establish himself as a force. With an excellent mix of pitches and no red flags in the mechanical or statistical departments, he’s a very intriguing young pitcher.
That said, his rise is so out-of-nowhere, and his period of dominance so small, that we still need the metaphorical smoke to clear before we can really get a better read on his MLB future. He’ll need to sustain his stuff and production over a full season at a higher level before I could be truly comfortable calling him a truly elite pitching prospect. But he certainly has a lot going for him, and he could be a good #2 or #3 starter for the Cardinals, a team that has suddenly and dramatically turned its farm system around this season. Due to his age, he’ll need to move fairly quickly; if he were to just move one level at a time, Rosenthal would be nearly 25 by the time he’d make the majors. But if he maintains his stuff, command, and groundball ability, he’ll skyrocket up lists next year, if he hasn’t already.
Previous installments in the Seedlings To Stars 2012 Top 100 Prospects:
For more on the Cardinals, check out Redbird Rants!