During the 2010-2011 off-season, the Pittsburgh Pirates claimed left hander Aaron Thompson off of waivers from the Washington Nationals. Thompson was a former first round pick for the Florida Marlins during the 2006 draft, and was eventually traded to Washington in exchange for first baseman Nick Johnson. During the 2009 season, the 6′ 2″, 190 pound left hander had a 3.93 ERA in 146.2 innings at the AA level between the two organizations. However, things fell apart for Thompson in 2010.
He remained at the AA level with Washington, putting up a 5.80 ERA in 136.2 innings. He did move up to AAA for one start, where he allowed one run on five hits and three walks in five innings. Washington eventually designated him for assignment, only for the Pirates to claim him, and return him to AA to start the 2011 season.
Thompson got off to a strong start this year, allowing one run on three hits in 12 innings, with a 7:2 K/BB ratio in his first two starts. Things went downhill from there. He posted a 6.07 ERA in his next nine starts, spanning 43 innings, and was removed from the rotation. After being removed from the rotation, Thompson put up a 5.65 ERA in his remaining time at the AA level, although he did have a 2.25 ERA in his last seven outings. He has since moved up to AAA, where he’s gotten off to a good start, with one earned run on six hits in 7.2 innings, along with a 5:1 K/BB ratio.
I saw Thompson twice early in the season with Altoona. His former 90-91 MPH fastball that touched 93 was gone. Instead his top speed was in the 89-90 MPH range. Thompson wasn’t as bad as his numbers suggested in the two starts I saw (10 IP, 4 ER, 13 H, 10:3 K/BB ratio). In the first outing he started off with five shutout innings, before falling apart in the sixth. In the second outing he only ran in to trouble in the third inning due to poor defense. But I wouldn’t say Thompson was dominant in either outing. His upside looks more like a middle reliever in the Tony Watson mold, although I would rate Watson higher due to his success in AA, and his ability to work in the low-90s with his fastball. However, I’d doubt that upside will be seen with the Pirates, as Thompson is down on the depth charts as far as left handers go, falling behind Watson, Justin Wilson, and Daniel Moskos in the upper levels.