SAN DIEGO (AP) Running back Ryan Mathews is targeting the Chargers' Sept. 10 season opener against the Oakland Raiders for his return from a broken collarbone.

Mathews was injured on his first carry of the preseason in the first quarter of the Chargers' game against the Green Bay Packers on Thursday night. He had surgery on Friday and the Chargers said he would miss four to six weeks.

Coach Norv Turner said it'll take a ``fortunate'' recovery for Mathews to play in four weeks.

Mathews led the Chargers with 1,091 yards rushing and a 4.9-yard average last season, earning him a trip to the Pro Bowl.