The San Diego Chargers signed Charlie Whitehurst, whom they traded to Seattle two years ago for a pair of draft picks.

The quarterback comes back to serve as Philip Rivers backup, because the Chargers also released incumbent backup Billy Volek, says the San Diego Union-Tribune.

The Chargers also signed safety Atari Bigby to a two-year deal, and also may be on the verge of losing running back Mike Tolbert, according to the Union-Tribune's website.

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Terry McCormick covers teh Titans for TitanInsider.com