Addition by subtraction

Would the Milwaukee Brewers' offense be better without a struggling Casey McGehee? Jerry Lai/US Presswire

As teams approach the 81-game milestone that marks the official midpoint of the season, it's become clear that some of last winter's best-laid plans have already gone awry. However, it's often not the presence of an underperforming player that defines a team's season, but how the team attempts -- or fails to attempt -- to correct that weakness. Clubs that stay content with subpar production for too long run the risk of finding themselves excluded from October, while those that respond proactively can salvage a season before it runs off the rails.

Some teams already have acted to address obvious deficiencies. After watching Jack Hannahan hit .171/.272/.240 since May 4 and backup Adam Everett hit .217/.277/.233 on the season, the Indians decided not to let cold bats at the hot corner sink their surprising season, calling up top prospect Lonnie Chisenhall on Monday to fill the offensive void. Some other clubs still suffering from counterproductive contributions could learn from the Indians' example.

The least productive position in baseball this season has been first base in Baltimore, where Derrek Lee and an assortment of part-timers led by Luke Scott and Brandon Snyder have combined to play nearly two full wins below replacement level (WARP), courtesy of total breakdowns at the plate, on the bases and in the field. Of course, the Orioles wouldn't make the playoffs even if they could replace their first-base flops with Prince Fielder the rest of the way.

What we're really interested in are the positional black holes that might actually pull a team out of the playoffs. With that in mind, here are this season's 10 least productive positions (by WARP) on contending teams, along with recommendations for how each club can try to fix its flaw from within: