Off-day notes: D-Rob, Joba, Aardsma

Not much going on today -- the calm before the storm of six games against the first-place Tampa Bay Rays and the surprising Mets -- but a couple of notes on the walking wounded pitchers:

David Robertson: He will throw a bullpen today. He is at the beginning of the process of bullpens, batting practice sessions and, eventually, rehab games, and is still not expected back before mid-June.

Joba Chamberlain: As Rob Parker reported over the weeked from Detroit, Joba threw off that oddity of modern rehabilitation, the "half-mound,'' but is still unable to run on his ankle -- which he dislocated during spring training -- so no real timetable is possible yet.

David Aardsma: Had Tommy John surgery a month after Joba last season, so was not counted on at all for 2012. But he has progressed so well in his rehab that he is now considered a strong possibility to pitch for the Yankees this season. Last week, Aardsma tweeted to me that he would be ready by early July; Brian Cashman says August or September is more likely.