Pitcher Josh Shortslef has been added to the 40-man roster; reliever Mike Johnston has cleared waivers.
Here's WTM's writeup on Shortslef. He's a lefty starter who has decent but not electric stuff, has missed a ton of time with injuries, has never struck out all that many batters, and will be 25 next season. He's a Cam Bonifay draftee - he was picked in the sixth round in 2000.
I'm not going to go so far as to say that Shortslef has no chance of having a big-league career, but he's not a good prospect at all. That the Pirates are now filling their last 40-man roster spots (and, in many cases, their last few 25-man roster spots) with players like Shortslef, Rajai Davis, Carlos Maldonado and Shane Youman suggests an alarming lack of depth in the Pirates' minor league system.