It seems performance wasn't the only reason for Greisinger coming off the active roster today. According to the Giants, Greisinger visited a hospital and got an MRI on his right elbow and was diagnosed with arthritis (or maybe just an inflammation) in the right elbow.
Seth Greisinger (YOM) was taken off the active roster today due to poor performance. Greisinger did complain of back tightness during a start on the 24th, but this move doesn't appear to have anything to do with that.
Greisinger went 0-1 in four starts and gave up 9 runs (8 earned) on 21 hits (including 3 homers), 10 strikeouts, and 1 walk over 14.2 innings of work.