San Diego Chargers running back Ryan Mathews has a sprained medial collateral ligament in his right knee and will be out for an undetermined amount of time. Mathews was taken off the field on a cart Sunday after hurting his knee trying to recover his own fumble in the fourth quarter of a 30-21 victory against the Seattle Seahawks. The Chargers didn't say to what degree the ligament was injured, which would help narrow down how long Mathews is expected to be out. ''In all fairness to him and the training staff, everyone recovers differently,'' coach Mike McCoy said Monday. More...