Andrew Bailey, who hasn't pitched since late spring training after a collision with the Pirates' Alex Pressly behind first base, threw off of a mound in his first bullpen session since the subsequent April surgery to repair the torn ulnar collateral ligament in his thumb. It was just 25 pitches, as Bailey hasn't built up his arm strength again -- spring training is a distant memory now that it's June -- but it's the first real, baseball-like work he's done in the rehab process.
His second bullpen session will come on Friday, and there are expected to be two more at Fenway Park during the Red Sox homestand. After that comes pitching to live hitting, but as of yet, there's no schedule in place for a minor-league rehab assignment. That will all depend on how quickly Bailey can get his arm strength back, and how well he responds to these bullpen sessions.
The Red Sox bullpen has been one of their strongest components this year after a rough start to the season, but the addition of Bailey, who owns a 2.07 ERA, strikeout per inning, and 3.6 K/BB in his 174 career innings, would obviously be a massive boost to the club's chances anyway. Either he could close, as was his initial role, pushing Alfredo Aceves back into the high-leverage, multi-inning role he occupied during 2011, or he could act as another reliable setup man for Aceves. It's likely the former will be what happens, and that's likely the preferable situation -- more Aceves is a good thing, and Bailey has a history of dominating as a closer.