The Cubs have placed 34-year old righty reliever Kerry Wood on the 15-day disabled list, retroactive to April 14th due to right shoulder fatigue. Wood has pitched in 4 games (0 starts) for the Cubs so far this year and he is 0-1 with a 11.57 ERA and a 2.57 WHIP. The Cubs have called up 27-year old righty reliever Scott Maine to replace Wood in the bullpen. Maine has pitched in 5 games (0 starts) in AAA-ball so far this year and he was 1-0 with 1 save, a 1.42 ERA and a 0.63 WHIP. He has pitched in 20 games (0 starts) in his first two years with the Cubs and he is 0-0 with a 4.95 ERA and a 1.50 WHIP. The Cubs hope Wood gets healthy soon, because they are going to miss him while he’s out of action.

25-year old lefty swinging outfielder Tony Campana is off to a good start in AAA-ball for the Cubs. Campana has played in 12 games in AAA-ball so far this year and he is 17 for 46 (.370 avg, .880 OPS) with 9 runs scored, 1 homer, 3 RBIs and 8 stolen bases. He was solid with the Cubs last year in his first taste of the majors when he played in 95 games in which he was 37 for 143 (.259 avg, .604 OPS) with 24 runs scored, 1 homer, 6 RBIs and 24 stolen bases. Campana is going to force the Cubs to call him back up if he keeps raking at the plate like he is right now.

The Chicago Cubs have a six pack of rookies who could make an impact in 2012. Here’s a look at them:

Brett Jackson: 23-year old lefty swinging outfielder Brett Jackson comes into this season as the Cubs’ #1 prospect according to Baseball America. Jackson played in 115 games in AA+AAA-ball last year and he was 118 of 431 (.274 avg, .869 OPS) with 84 runs scored, 20 homers, 58 RBIs and 21 stolen bases. He has now played in 296 games in his first three years in the minors and he is 331 of 1,133 (.292 avg, .884 OPS) with 237 runs scored, 40 homers, 160 RBIs and 64 stolen bases. If one of the Cubs’ current starting outfielders gets injured or dealt, Jackson will get his chance to show what he can do in 2012.

Anthony Rizzo: 22-year old lefty swinging 1B Anthony Rizzo was the Padres’ #1 prospect before he was dealt to the Cubs. Rizzo played in 49 games for the Padres last year in his first taste of the majors and he was 18 of 128 (.141 avg, .523 OPS) with 9 runs scored, 1 homer, 9 RBIs and 2 stolen bases. Rizzo also played in 93 games in AAA-ball last year and he was 118 of 356 (.331 avg, 1.056 OPS) with 64 runs scored, 26 homers, 101 RBIs and 7 stolen bases. Rizzo has now played in 375 games in his first five years in the minors and he is 425 of 1,436 (.296 avg, .880 OPS) with 234 runs scored, 64 homers, 281 RBIs and 21 stolen bases. The Cubs are going to be careful with Rizzo as he was overwhelmed by major league pitching last year. That being said, they are going into the 2012 season with Bryan LaHair as their starting 1B.

Adrian Cardenas: 24-year old lefty swinging 2B Adrian Cardenas was the A’s #12 prospect coming into this season according to Baseball America. The Cubs snapped Cardenas up on waivers when the A’s tried to sneak him through. Cardenas played in 127 games in AAA-ball last year and he was 154 of 491 (.314 avg, .791 OPS) with 70 runs scored, 5 homers, 51 RBIs and 13 stolen bases. He has now played in 643 games in his first six years in the minors and he is 749 of 2,475 (.303 avg, .780 OPS) with 374 runs scored, 29 homers, 323 RBIs and 77 stolen bases. Cardenas could help the Cubs at some point in 2012.

Dave Sappelt: 25-year old righty swinging outfielder David Sappelt was the Reds’ #16 prospect when the Cubs dealt for him over the winter. He played in 25 games for the Reds last year and he was 26 of 107 (.243 avg, .607 OPS) with 14 runs scored, 0 homers, 5 RBIs and 1 stolen base. He also played in 120 games in AA+AAA-ball last year and he was 93 of 297 (.313 avg, .834 OPS) with 40 runs scored, 7 homers, 29 RBIs and 4 stolen bases. Sappelt has now played in 405 games in his first four years in the minors and he is 498 of 1,612 (.309 avg, .821 OPS) with 230 runs scored, 31 homers, 184 RBIs and 82 stolen bases. Sappelt will be with the Cubs at some point in 2012.

Welington Castillo: 24-year old righty swinging catcher Welington Castillo comes into the 2012 season as the Cubs’ #6 prospect according to Baseball America. Castillo played in 4 games for the Cubs last year and he was 2 for 13 (.154 avg, .308 OPS). He has now played in 11 games in his first two years with the Cubs and he is 8 for 33 (.242 avg, .719 OPS) with 3 runs scored, 1 homer and 5 RBIs. Castillo also played in 75 games in Rookie+A+AAA-ball last year and he was 79 of 275 (.287 avg, .876 OPS) with 46 runs scored, 16 homers and 42 RBIs. He has now played in 438 games in his first six years in the minors and he is 399 of 1,506 (.265 avg, .753 OPS) with 194 runs scored, 55 homers, 221 RBIs and 3 stolen bases. Castillo could make the Cubs out of spring training as Geovany Soto’s backup.

Steve Clevenger: 25-year old lefty swinging catcher Steve Clevenger comes into this season as the Cubs’ #21 prospect according to Baseball America. He played in 2 games for the Cubs last year and he was 1 for 4 (.250 avg, .900 OPS) with 1 run scored. He also played in 120 games in AA+AAA-ball last year in which he was 127 of 398 (.319 avg, .857 OPS) with 51 runs scored, 8 homers, 54 RBIs and 2 stolen bases. Clevenger has now played in 543 games in his first six years in the minors and he is 560 of 1,816 (.308 avg, .790 OPS) with 228 runs scored, 21 homers, 254 RBIs and 18 stolen bases. Clevenger will likely help the Cubs out at some point in 2012.

The Cubs have to be really impressed with 22-year old righty swinging outfielder Evan Crawford this year. Crawford has played in 100 games in A-ball so far this year and he is 123 for 385 (.319 avg, .802 OPS) with 65 runs scored, 2 homers, 47 RBIs and 29 stolen bases. He has now played in 274 games in his first three years in the minors and he is 302 of 1,051 (.287 avg, .739 OPS) with 173 runs scored, 7 homers, 109 RBIs and 70 stolen bases.

31-year old righty starter/reliever Dave Bush has opted out of his minor league contract with the Cubs and he has become a free agent. Bush started 5 games in AAA-ball for the Cubs and he was 1-2 with a 6.14 ERA and a 1.68 WHIP. He also pitched in 17 games (3 starts) for the Rangers earlier this year and he was 0-1 with a 5.79 ERA and a 1.50 WHIP. This will be no loss for the Cubs as Bush was rather unimpressive in the minors.