| Date | Player | Position | Transaction |
|---|---|---|---|
| May 22 | Josh Thole | C | Transferred to 15-Day DL by NY Mets (Concussion) |
| May 21 | Chris Schwinden | SP | Sent to Minors by NY Mets |
| May 21 | Vinny Rottino | LF/1B | Called Up from Minors by NY Mets |
| May 20 | Chris Schwinden | SP | Called Up from Minors by NY Mets |
| May 19 | Jordany Valdespin | SS/2B/LF | Sent to Minors by NY Mets |
| May 19 | Jeremy Hefner | RP/SP | Called Up from Minors by NY Mets |
| May 19 | Pedro Beato | RP | Sent to Minors for Rehabilitation by NY Mets |
| May 17 | Robert Carson | RP | Called Up from Minors by NY Mets |
| May 17 | D.J. Carrasco | RP | Designated for Assignment by NY Mets |
| May 11 | Vinny Rottino | LF/1B | Sent to Minors by NY Mets |
| May 11 | Ronny Cedeno | SS/2B/3B | Recalled From Minors Rehab by NY Mets |
| May 10 | Ronny Cedeno | SS/2B/3B | Sent to Minors for Rehabilitation by NY Mets |
| May 8 | Pedro Beato | RP | Transferred to 60-Day DL by NY Mets (Right shoulder stiffness) |
| May 8 | Rob Johnson | C | Purchased From Minors by NY Mets |
| May 8 | Josh Thole | C | Placed on 7-Day DL by NY Mets (Concussion) |
| May 7 | Jordany Valdespin | SS/2B/LF | Called Up from Minors by NY Mets |
| May 6 | D.J. Carrasco | RP | Recalled From Minors Rehab by NY Mets |
| May 5 | Jordany Valdespin | SS/2B/LF | Sent to Minors by NY Mets |
| May 4 | Chris Schwinden | SP | Sent to Minors by NY Mets |
| May 4 | Mike Pelfrey | SP | Transferred to 60-Day DL by NY Mets (Swollen right elbow) |
| May 4 | Vinny Rottino | LF/1B | Purchased From Minors by NY Mets |