Collateral Damage Daily for May 31

Things didn't go too well for Matt Kemp on Wednesday night. He had to leave the game after only one inning because of a recurrence of left hamstring pain. It's never a good sign when an injury returns so quickly; Kemp could make a second trip to the DL. Troy Tulowitzki also came out of the game Wednesday with a left groin injury. He's dealt with multiple nagging groin and leg injuries in 2012, but this may be the one that puts him on the DL.

Additions

• Travis Hafner was placed on the DL retroactive to May 24 because of his troublesome right knee. He is scheduled to have surgery today, and early estimates are that he will miss about four to six weeks. This assumes that the torn piece of meniscus simply needs to be trimmed out. If doctors need to repair it, the recovery time may be doubled. His long-term production should not change, except taking away the discomfort that has caused a pretty poor May at the plate. You can imagine that trying to twist on a painful knee and hit at the same time can be quite difficult. The surgery today should help to take care of this.
• Ronny Cedeno was placed on the disabled list because of a strained left calf. Cedeno already was on the disabled list earlier in the year because of an intercostal strain, and his calf injury leaves the Mets in a rough spot at shortstop. Omar Quintanilla will get the bulk of the playing time, though Jordany Valdespin will get some time here and there.
• Doug Fister was placed back on the DL after re-aggravating his left costochondral injury. The spot where the cartilage meets the ribs can be very difficult to heal in part because of a relative decreased blood supply compared to the surrounding tissues. The area seems to have bothered Fister since he's been activated, more so lately though. The command and finish on his pitches were there, and the Tigers' staff noticed his arm slot changing. There's no estimate for when he will return, but we should get one within the next few days.