It’s not hard to find a list of any MLB team’s top prospects, but will any of those prospects be ready to contribute in 2012? We’re here to help you prepare for the unexpected by ranking each team’s top five minor league prospects from a fantasy perspective. While they may not be the team’s brightest stars (though many of them will be) they’re the names you’ll need to know when the unexpected happens. Make sure to check out our other top minor league prospects posts for each of the 30 teams.

Potential roster vacancies: 1B, OF, C, SP

Last season the Chicago Cubs won just 71 games en route to the second worse record in the National League. The Houston Astros, victors just 56 times in 2011, were so bad that the NL owners got together and decided the club was an embarrassment and had to go. Despite the lack of wins coming from the north side of Chicago (actually, the south side finished with a losing record as well), there isn’t a lot of room for minor leaguers to make an impact in the coming season. Geovany Soto will be the team’s catcher, Darwin Barney and Starlin Castro will man the middle of the infield, and Ian Stewart stands responsible for third base.

Until the team can find someone to take Alfonso Soriano, his poor contract and moderate production will be stuck in left field. Marlon Byrd will once again patrol center, and the Cubs acquired David DeJesus this offseason to play right. Utility guys Jeff Baker, Blake DeWitt and Reed Johnson are stashed on the bench, so by my estimation that leaves just one position in flux: first base. Bryan LaHair, a career minor leaguer, will keep first base warm until the recently acquired Anthony Rizzo is ready to be an everyday major leaguer. Aside from that, injury seems to be the only way someone is getting a chance.

As of now, Matt Garza is the team’s ace, but there’s plenty of trade talk surrounding the 197 strikeouts and 3.32 ERA from a year ago. Let’s say, for the sake of argument, that the Cubs trade Garza for prospects. That leaves the team with Ryan Dempster, Paul Maholm (just signed), Randy Wells and Chris Volstad (acquired in the Carlos Zambrano trade) as the team’s other rotation arms. But lo! They also added Andy Sonnanstine to the mix this season, a guy who split time in Tampa Bay between the bullpen and rotation. I actually like a lot of the arms that the Cubs have, but without Garza (heck, even with Garza) they lack front of the rotation starters and have no proven rotation depth after Sonnanstine. This rotation is ripe for the picking.

Carlos Marmol will be the team’s closer, but he’s prone to control problems and even lost his job for a short time last season. After him there’s a few names we’ve seen before (James Russell, Manny Corpas, Jeff Samardzija) and a few many of us haven’t (Chris Carpenter, Scott Maine, Lendy Castillo). If Marmol goes down, who steps up?

Chicago Cubs Top 5 Minor League Prospects for Fantasy Baseball

1. Anthony Rizzo, 1B

Rizzo was the centerpiece of the trade that sent Adrian Gonzalez to Boston. Then the Red Sox collapsed, Theo Epstein went to Chicago and one of his first moves was to re-acquire Rizzo. Rizzo played 49 disastrous games with the Padres last season, and scouts said his bat looked slow. Many wondered if he actually had what it takes to make it as a big leaguer. In fact, they’re still wondering that since Rizzo hasn’t had a chance to prove doubters wrong. Epstein and Cubs executives say they know what’s wrong with Rizzo and they can fix him. Rizzo has (had?) .300/30/100 potential, so assuming the Cubs can the cure for his ailing swing, he’s the most important guy to keep an eye on in this organization. If LaHair plays well he can buy Rizzo some time to work things out in Triple-A, but the job will soon be Rizzo’s.

2. Brett Jackson, OF

Jackson split time last season between Double-A and Triple-A, hitting 20 homers and stealing 21 bases across the two levels, but he actually performed better at the higher stop…or did he? His .297 average topped anything he’d done since Single-A ball back in 2010, but he struck out more and walked less to do it. That doesn’t quite jive. It’s assumed that Jackson will soon supplant Byrd in center field, and the Cubs have already made some room out there by shipping Tyler Colvin to Colorado for Stewart, so when the team feels Jackson is ready, he should get the lion’s share of at-bats. Be warned, though. His strikeout rate is generally very high and it will most likely be a rocky transition.

3. Wellington Castillo, C

Castillo is projected to be the backup catcher on the major league roster, so if something happens to Soto we’ll see a lot of Castillo. Last season in 61 games at Triple-A he batted .286 with 15 homers, but he strikes out over 20 percent of the time and walks just under 10 percent. He could be another one of those low average, moderate power catchers you can find late in your fantasy draft.

Bonus prospect: Another catcher to keep an eye on Steve Clevenger. He could bat near .280 with a strikeout rate half of Castillo’s, but he doesn’t have the same kind of pop. He’ll likely begin the year in Triple-A.

4. Casey Coleman, SP

Coleman started 17 games for the Cubs last season and appeared in two more in relief, so he’s not a rookie this year, but he’s their most major league-ready pitching prospect. Most think Trey Mcnutt is the team’s top pitching prospect — you may have heard his name rumored to be part of Boston’s yet-to-be-decided-on compensation package for Epstein — but Coleman will get the first crack. With a 5.5 K/9 and 2.9 BB/9 in his minor league career, I don’t like his chances at success in the least. However, in the event of injury, someone has to pitch the innings.

5. Chris Carpenter, RP

Carpenter is part of the Cubs’ projected opening day bullpen and could be in line for some saves if Marmol ever loses his job. He probably won’t be the first option, but he could be the second. Or the first. There’s really no way to know with so few proven arms out there. It’ll all depend on who’s pitching the best at the time Marmol hypothetically implodes. Carpenter was a starter in his first three minor league seasons, last year transitioning to the bullpen. For that reason I’ll evaluate him on his 2011 rates alone: a 7.2 K/9 and a 5.7 BB/9. Gross.