The A’s have traded 29-year old righty swinging OF Matt Holliday to the Cardinals for 22-year old lefty swinging 3B Brett Wallace, 21-year old lefty swinging outfielder Shane Peterson and 24-year old righty starting pitcher Clayton Mortensen. Holliday played in 93 games for the A’s this season and he was 99 for 346 (.286 avg, .831 OPS) with 52 runs scored, 11 homers, 54 RBIs and 12 stolen bases. The A’s will miss Holliday’s bat this season as he was starting to heat up but they got a nice return for him. Brett Wallace was the #2 rated prospect in the Cardinals’ minor league system coming into this season according to Baseball America. Wallace has played in 94 games in AA+AAA ball this season and he is 101 for 350 (.289 avg, .797 OPS) with 44 runs scored, 11 homers and 35 RBIs. If the A’s are able to trade either Mark Ellis or Adam Kennedy soon they would likely bring Wallace up to start at 3B. Clayton Mortensen as the #6 rated prospect in the Cardinals’ system heading into this season according to Baseball America. Mortensen has pitched in 17 games (all starts) in AAA-ball this season and he is 7-6 with a 4.37 ERA and a 1.30 WHIP. He also made his major league debut in relief for the Cardinals this season and he was 0-0 with a 6.00 ERA and a 2.00 WHIP. If the need arises in the starting rotation the A’s might give Mortensen a chance this season. Shane Peterson has played in 94 games in A+AA ball this season and he was 106 for 359 (.295 avg, .784 OPS) with 42 runs scored, 7 homers, 46 RBIs and 12 stolen bases. Under the circumstances this was a good trade for the A’s.