| Date | Player | Position | Transaction |
|---|---|---|---|
| May 23 | Steven Hill | C/1B | Purchased From Minors by St. Louis |
| May 22 | Aaron Bates | 1B | Signed to a Minor League Contract by St. Louis |
| May 21 | Lou Montanez | RF/LF/CF | Signed to a Minor League Contract by St. Louis |
| May 20 | Matt Adams | 1B | Purchased From Minors by St. Louis |
| May 18 | Brandon Dickson | SP/RP | Called Up from Minors by St. Louis |
| May 18 | Adron Chambers | CF/LF/RF | Called Up from Minors by St. Louis |
| May 16 | R.J. Swindle | RP | Released by St. Louis |
| May 16 | Clay Zavada | RP | Signed to a Minor League Contract by St. Louis |
| May 16 | J.C. Romero | RP | Cleared Waivers and Became a Free Agent by St. Louis |
| May 15 | Shane Robinson | CF/RF/LF | Called Up from Minors by St. Louis |
| May 14 | J.C. Romero | RP | Released by St. Louis |
| May 14 | Eduardo Sánchez | RP | Called Up from Minors by St. Louis |
| May 12 | Shane Robinson | CF/RF/LF | Sent to Minors by St. Louis |
| May 4 | Erik Komatsu | CF/RF/LF | Acquired Off Waivers from St. Louis to Minnesota |
| May 1 | Erik Komatsu | CF/RF/LF | Designated for Assignment by St. Louis |
| May 1 | Allen Craig | 1B/LF/RF | Recalled From Minors Rehab by St. Louis |