Per Hard Ball Talk:

Bad news came back for Joba Chamberlain a few minutes ago: he has a torn elbow ligament.

Joe Girardi just told the Yankees beat writers that, while a decisions hasn’t been made yet, he believes that Tommy John surgery is likely. That would obviously end Joba’s season. And would kill the majority of next season.

The weird thing is that there wasn’t any warning or any obvious incident of injury here. Until he was shut down yesterday, he had been pitching fine. There was no walk-off-the-mound-holding-his-elbow moment. No unexplained implosion brought on by a sudden loss of velocity. He just got shut off like a switch. Guess that’s just how ligaments roll sometimes.

Going into the season the idea was that the Yankees bullpen was going to be all aces, with Mariano Rivera owning the ninth, Rafael Soriano setting things up in the eighth and Chamberlain manning the seventh most days.  Now Mariano stands alone.