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Frank Victores/Associated Press

NFL free agency is a way for teams to complement the draft and add the talent necessary to contend for the playoffs and more.

But it is akin to sketching on paper with a pencil. Overzealous maneuvers and outright mistakes can be costly in more than a financial sense—sometimes swinging things for the worse as opposed to having no impact at all.

Recent examples that come to mind include the Arizona Cardinals' decision to throw millions at Sam Bradford, who played three games, and the Washington Redskins' big contract (five years, $40 million) with wide receiver Paul Richardson, who caught 20 passes before going on injured reserve.

Bradford's injury history was a problem well before he got cut prior to Week 10 so the Cardinals could recoup a compensatory selection, while Richardson was a one-hit wonder before joining Washington and getting hurt. The following free agents are the top must-avoid names for teams this year for varying reasons. Injury history, age and simple cost-effectiveness projections factor into this analysis.