Joba Chamberlain threw off a half-mound in Tampa yesterday as he continues to come back from the right ankle injury he suffered during spring training. "I've always said I believe he'd be back for us this year," Yankees manager Joe Girardi said of the dislocation and torn ligaments Chamberlain suffered when he fell on a trampoline in Florida. "This instills my belief." Girardi is still reluctant to put a timetable on Chamberlain's return because "he has other hurdles to clear." The manager said he is particularly confident Chamberlain's arm will be fine after last year's right elbow surgery.