Fantasy Baseball Sleepers 2012: Jim Johnson and Relievers Ready to Explode

Just like every MLB franchise, your fantasy baseball team needs an underrated reliever in order to challenge for the league crown.

With Opening Day right around the corner and fantasy baseball leagues popping up around the country, owners must draft wisely and look for sleepers that will make the difference in their matchups.

Join Bleacher Report as we take a closer look at some relievers ready to explode this season.

Jim Johnson, Baltimore Orioles

The O's veteran will have the advantage over fellow Baltimore closers this spring when it comes to landing the starting job, and his 2.67 ERA in 69 appearances last season certainly doesn't hurt his chances.

Although he has some improving to do, Johnson will certainly get plenty of time on the mound, with the Orioles liking to struggle this season. Even his relieving competition, Matt Lindstrom, will be on the hot seat if he gets the nod to start 2012. 

Sean Marshall, Cincinnati Reds

With free-agent addition Ryan Madson gone for the season because of a torn elbow ligament, former Chicago Cub Sean Marshall is primed for an opportunity with the Reds.

Marshall made 78 appearances in 2011, posting 79 strikeouts, along with six wins and five saves. He finished the year with a 2.26 ERA and a superb 9.4 strikeouts per nine innings. 

Jonathan Broxton, Kansas City Royals

Broxton joined the Royals this offseason after playing his previous seven MLB seasons with the Los Angeles Dodgers. His 2011 season was hardly impressive, featuring 14 appearances and a 5.68 ERA, but he should see the mound more now that Joakim Soria will miss the season while recovering from Tommy John surgery.

The experience Broxton brings to the mound late in the game makes him a dependable reliever, but he certainly brings a fair share of risk considering that his speed and zip looked off at times last season.