21-year old lefty swinging 2B Adrian Cardenas was the #5 rated prospect in the A’s minor league system coming into this season according to Baseball America. He was the key of the Joe Blanton trade with the Phillies last season. He has played in 97 games in AA+AAA ball this season and he is 117 for 387 (.302 avg, .786 OPS) with 64 runs scored, 3 homers, 66 RBIs and 6 stolen bases. He has had some trouble adjusting to AAA pitching but he could get called up in September if he gets back on track.

The Oakland A’s will likely give 26-year old lefty reliever Jay Marshall another chance soon if he keeps pitching like he is right now. He has pitched in 38 games (0 starts) in AAA-ball this season and he is 3-1 with 3 saves, a 1.83 ERA and a 1.07 WHIP.

21-year old righty starting pitcher James Simmons is on the rise for the A’s. He was the #3 prospect in the A’s minor league system coming into this season according to Baseball America and he’s showing why this year. Simmons has started 15 games in AA ball for the A’s this season and he is 4-4 with a 3.28 ERA and a 1.15 WHIP. Look for the A’s to take their time with Simmons as they have a lot of other good young pitchers in their farm system.

24-year old righty swinging 2B Jesus Guzman has been dominating the minor leagues this season. He has played in 87 games in AA+AAA ball and he is 124 for 365 (.340 avg, .925 OPS) with 58 runs scored, 15 homers, 78 RBIs and 5 stolen bases. If Mark Ellis is either traded this month or gets injured the A’s will likely give Guzman his big chance at the majors.

Vin Mazzaro has been pitching great this season in AA ball for the A’s. The 21-year old righty starting pitcher was ranked as the #18 prospect in the A’s minor league system coming into this season according to Baseball America’s Prospect Handbook. That’s despite the fact that Mazzaro was pretty bad in his two first seasons of pro ball. In his first two years he started 52 games in A-ball and he was 18-21 with a 5.21 ERA. But, the lights have apparently went on inside of Mazzaro’s head as he has been dominating so far this season in AA. Mazzaro has started 13 games this season in AA ball and he is 7-3 with a 2.24 ERA and a 1.13 WHIP. He might earn a trip to the majors later this season if he keeps pitching like he is right now.