The GCL pitching staff saw two real breakouts this year. Roman Mendez is one of them. Before this year, for many Sox fans Mendez was the best Sox Prospect they'd never heard of (I believe I am borrowing this line from someone—probably a scout—but unfortunately the source escapes me at the moment). At the age of 17, Mendez had a very good year in the DSL, maintaining a 2.65 ERA over 51 innings in 11 starts, striking out 46 and walking 16. Starting the year barely 18, somewhat underweight for his size, and facing the improved talent in the GCL, SoxProspects.com had this year pegged as a challenge for him.
It was anything but. Mendez pitched a similar number of innings (49.2), lowering his ERA to just under 2, maintained his strikeout numbers, and actually managed to decrease his walks to a paltry 8. Already able to get his fastball up to 96 (averaging around 93), Mendez projects to add even more velocity, and brings an already good slider to the table while working on a change. Look for Mendez to start next season at Lowell, and hopefully work on increasing his innings total so he can handle a full-season team like Greenville in 2011.
The other half of the breakout pair, lefty Manny Rivera is nearly a year older than Mendez. A converted closer, Rivera has produced good results as a starter, posting a 2.24 ERA last year in the DSL and a microscopic 1.19 ERA this year in the GCL. His strikeout and walk numbers are both a little higher than Mendez' at 58:19 in 2008 and 50:14 in 2009. Manny throws a low-90s fastball, advanced change, and is working on a curve. If there's a knock on Rivera, it's an inconsistent release point which has lead to some of his slightly high walk numbers, though he's improved on that since last year. Also of note is the fact that half of the runs he allowed were unearned, suggesting a somewhat artificially deflated ERA.
Let's get this out of the way: Tyler Wilson did not exactly have a good year. He pitched 8 innings, giving up 5 runs, striking out 11 while walking 4. Small sample size, of course, applies, but it's not a good year either way. What Tyler Wilson does have is projectability. A low-90's fastball that seems likely to get up to 95 and 2 off-speed pitches (slider, curveball) that could be plus pitches if he can develop them. Wilson is almost 20, so being stuck in the GCL another year might keep him behind typical age progression, but Wilson is still worth keeping an eye on.
Swen is all about control. In 43 professional innings with the GCL Sox over the last 2 years, the soon-to-be-19-year-old Hujier has walked 1 batter. One. Currently, he doesn't have outstanding stuff. His fastball lacks velocity, and his secondary pitches all need a good deal of work (though according to him, that has been a focus of his this year). But he does project to fill out over time, and any pitcher who has control like this stands out like a sore thumb (but in a good way). Hujier has acted out of the pen for all but 1 of his appearances, and likely continues to project as a reliever unless he undergoes some dramatic changes as he fills out.
If anyone has gone under the radar since the 2008 draft, it's been Kyle Stroup. A 50th round pick, Stroup was projected to go in the first 10 rounds, but dropped dramatically due to bonus demands (ultimately received $150,000). Stroup has a strong arm that can reach the mid-90's with his fastball and sits around 92-93, but stands to add velocity with strength training and can likely hit the mid-90s consistently and possibly top out higher. Kyle also has a knuckle curve with plus potential and an average splitter and change. Stroup pitched out of the pen this year, but is almost guaranteed to be a starter long term with an arm that doesn't tire. After posting an ERA of 4.50 this year in 24 innings, Stroup has some issues to work on. Walking 14 batters in 21 innings isn't exactly impressive, and he's been hittable, giving up 28. Look for Kyle to work on control next season, and possibly a move to the rotation.