With the health of Josh Johnson's shoulder in question, Yusmeiro Petit has gone from having a very remote chance of making Florida's rotation to having a good chance of starting the season in their rotation.
Petit is a guy who has generally been loved by most 'numbers guys' and considered only a fringe prospect by traditional scouts. Maybe ironically, after looking over his stats, I think the scouts may be onto something here.
Between 2003 and 2005 Petit pitched a combined 341.1 innings in the lower minor leagues (up to and including AA) and was dominant: 413 K with only 69 BB. He was significantly less effective at AAA in 2005 and 2006: 82 K and 26 BB in a combined 111.1 innings pitched. His brief opportunity in the majors was pretty consistent with his AAA performance: 20 K and 9 BB in 26.1 innings. In addition, he's had pretty bad HR/9 throughout his professional career, and was an extreme flyball pitcher in the only sample for which I have GB/FB data (the 26.1 innings in the majors).
So based on his AAA and Major League experience, we'd have to assume that he'll be a moderately effective major leaguer who is prone to high home run rates. Basically a #4 or #5 starter throughout his career. This is more or less what the scouts and 'tools guys' have been predicting for him for several years. Even when he was dominating at AA they said that his less than overwhelming fastball wouldn't convert well to the major leagues.
So is there hope for anything better from Petit? Maybe, for two reasons:
1. He's still only 22 years old. While youth isn't always the blessing for pitching prospects that it is for hitters, it means there's plenty of time for him to improve.
2. His performance in AA in 2005 was really exceptional. The competition at AA (where many top prospects are sent) typically isn't that much worse than AAA (where rosters are often filled with washed up or failed major leaguers) and he managed to strike out 130 batters in 117.2 innings with only 18 walks. Adjusted for the more difficult competition in the majors, that should indicate he's got the potential to be a decent #2 or #3 type starter. If that happens this year, then he's going to be a huge steal in fantasy drafts. Since you'll be able to get him late (probably undrafted in shallow mixed leagues), there's some upside without any real risk.