Chargers' Ryan Mathews misses practice Friday

San Diego Chargers running back Ryan Mathews missed practice Friday, casting doubt on his availability for a crucial contest Sunday against the Denver Broncos.

Mathews injured his ankle in the Chargers' Week 14 loss to the New England Patriots and failed to practice all week. He has battled ankles woes previously in his career.

If Mathews can't suit up Sunday, Donald Brown and Branden Oliver are expected to split carries.