Five trades to boost contenders

The Angels have depth at first base, and Mark Trumbo could fit well with the Rays. Jeff Gross/Getty Images

This offseason we've witnessed some massive, industry-shaking signings and blockbuster trades. But even the teams that made major moves still have some problems. With that in mind, here are five deals that would go a long way toward boosting the chances of a number of contenders. In some cases, both clubs have World Series aspirations and could benefit by trading from depth.

1. Arizona Diamondbacks trade LF Gerardo Parra to the Detroit Tigers for OF Andy Dirks, UT Don Kelly and LHP Andy Oliver

After signing free agent Prince Fielder and announcing that Miguel Cabrera will move back to third base, the Tigers have basically admitted that their corner-infield defense will take a step back in 2012 and beyond. To compensate, the Tigers should look to upgrade their defense elsewhere. Left fielder Delmon Young does not come in on the ball well and is an overall poor defender.