Stolmy Pimentel, 22 (he'll be 23 on February 1st), is the least known and perhaps most intriguing name who was part of the Hanny deal with Boston.
He was signed by the Red Sox in 2006 as a 16 year old from San Cristóbal of the Dominican Republic. His bonus was for $25,000, so the string bean teen wasn't considered an elite prospect at the time. That changed in a hurry.
Boston kept him home his first year, pitching for the DSL Red Sox in 2007. He went 3-1/2.90 ERA in 13 starts, striking out 60 hitters in 62 IP. He was named as the Bosox Minor League Latin Program Pitcher of the Year at seventeen.
Pimentel skipped a level and went to Lowell of the short-season NYPL for his American debut as the youngest starter in the league. He went 5-2/3.14 ERA in 11 starts for the Spinners and posted a strong whiff rate again with 61 K in 63 IP. Stolmy was named to the All-Star team and Baseball America rated him the Red Sox #10 prospect with the best changeup in the organization.
His star was taking off, so much that the Red Sox were ready to veto the trade that sent Manny Ramirez to the Dodgers and Jay Bay to Boston because of Pimentel, whom the Pirates wanted badly to be included in the deal. The Bucs instead settled on Craig Hansen, whose career has been derailed due to a nerve condition (he's now with the Mets organization, last throwing for Class A Savannah in 2012).
Stolmy moved up another step in 2009, joining Class A Greenville of the Sally League. His slash there was 10-7/3.82 in 23 starts covering 117-2/3 innings, with 7.9 K and 2.2 walks per nine. Fangraphs ranked him as the #6 prospect in the Sox system after the season, though he dropped of BA's Top Ten list.
He continued on his step-by-step journey, advancing in 2010 to High Class A Salem of the Carolina League. Pimentel's line was a workmanlike 9-11/4.06 in 26 starts lasting 128-2/3 frames. His K and walk rates took a bit of a hit, but he shaved a couple of hits per nine off the previous season, and it looked like he was beginning to learn to pitch instead of just throwing. It helped too that his fastball velocity picked up to the low-to-mid nineties.
Pimentel was named to the All-Star Futures Game with upside overcoming a very so-so stat line, and Boston added him to 40-man roster in November. Fangraphs ranked him as the Red Sox #5 prospect (#6 at BA), and evaluator Marc Hulet wrote "He...projects as a durable, innings-eater with the ceiling of a No. 3 starter."
Unfortunately, reality raised its head and bit him hard in 2011. Pimentel was sent to Class AA Portland in the Eastern League. In 15 starts and just 50-1/3 innings, his slash was 0-9/9.12 with horrible peripherals - 13.4 hits, 1.4 homers, 4.1 walks and only 5.4 K per nine. Pimentel was sent back to Salem, where he recovered his mojo a bit.
His most noticeable concerns were pitching behind in the count, a flat fastball, and a curve that hung more than dove (in fact, he dropped it that season and turned to a slider). He was named the Red Sox's No. 16 prospect by MLB.com entering the 2012 season and #23 by BA, his prospect status suddenly on life support.
The righty got back on the bike in 2012 at Portland, and in 22 starts he went 6-7/4.59 in 115-2/3 frames with his peripherals rebounding to acceptable, though not strong, levels. Boston was going through a 40-man roster crunch during the off-season and they didn't want to DFA the expendable Pimentel and lose him for no return. So they did the next best thing and used him as a lure for the Hanny trade, no doubt remembering the Bucs prior interest in him.
Pimentel throws a four-seamer in the 92-94 range, with a cutter that's a couple of ticks slower. His change is an above average-to-plus pitch, and his slider is a work in progress. He started to show a sinker last year, and that's a pitch the Pirate people know how to teach. So his toolkit now features an acceptable fastball/change up duet, and possibly starter's stuff if he gets comfortable with and can control either the sinker or slider.
Alex Speier of Boston's WEEI Radio said "He may still develop into a mid-to-late rotation starter with the
Pirates, and based on the progress he made with his delivery in 2012, along with Pimentel’s intelligence, work ethic and youth, it would be a mistake to rule out a developmental leap."
Pimentel's biggest problem moving ahead is that he's in his last option year, which means he has to be on the MLB roster by 2014 or could be lost. The Pirates will probably start him out in Class AAA Indy, and logic dictates they'll work him out of the bullpen. His fastball/change combo should play if he's only facing an order once.
In the big picture, a bullpen move could get Pimentel to Pittsburgh in 2014, and buys the Bucs a bit of time to straighten out his mechanics and add a third pitch to his repertoire. Ideally, they'd like to get him in the rotation eventually and if that's not in the cards, try to convert him into a back-end reliever. But hey, if he ends up in the Jared Hughes/Tony Watson mold of converted starters, that's fine, too.
Of course, none of the major league scenarios is a given; Pimentel has floundered in Class AA and may have hit his wall there. But he is an upside throw-in, and every so often you get to cash in your Lotto ticket.