As you've undoubtedly heard by now, the Pirates have promoted righty Wilfredo Boscan to the big leagues and optioned Steve Lombardozzi to Indianapolis. They also transferred Brandon Cumpton to the 60-day DL.
Boscan, 25, is a minor-league signee who's never pitched in the majors but who's had a pretty good season at Triple-A so far. I didn't think he'd play much of a role with this year's team, and it's likely he still won't, but here's why he's coming up now. The Pirates threw a billion pitches in an extra-inning game yesterday and needed bullpen help. Boscan is uniquely equipped to provide innings today (and it doesn't look like the Pirates will need a ton of them, judging from the game so far, but if it goes into extra innings, Boscan will be there). He's a starter, so he can work five or six frames as long as he doesn't blow up, and he hasn't pitched since last Sunday. Also, since he's likely a low-priority player for the Pirates, they can designate him for assignment later and not worry much in the unlikely event that he's claimed.