Chargers WR Vincent Brown, who broke his left ankle against the Cowboys on Saturday, is expected to be out at least eight weeks after undergoing surgery. Coach Norv Turner would like to keep Brown on the roster, but is uncertain if Brown will play this year.

 “I am hopeful,” Turner said of Brown contributing in 2012. “We don’t have to make a decision about that at this time. We will see how his recovery goes and we will see what happens over the next couple of weeks in terms of our football team.”

 If Brown does not go on the season ending IR list, six receivers will be kept on the 53-man roster until Brown returns somewhere in midseason.

 Turner’s decision to keep Brown off of the IR list is complicated by the injury to Ryan Mathews (broken clavicle). Four running backs are expected to be kept until Mathews is able to play. If an injury occurs to another player in preseason that requires an additional roster spot, it would be difficult to keep Brown on the roster.

 Mathews was originally projected to be out four to six weeks. That means the earliest he could return would be week 2 against the Titans. Mathews has pointed out that he’s a fast healer and has set a goal to play in the season opener against the Raiders. That would eliminate the need to carry a fourth RB and make it easier to keep Brown on the roster.  

 An early return for Mathews may not be practical. Dr. Neil Ghodadra, a former team doctor of the Chicago White Sox and Chicago Bulls, suggested Mathews could be out until after the team’s bye in week 7.

 “It takes six weeks for the bone to heal,” Ghodadra explained on NFL Fantasy Live. "Even after you fix it with the clavicle plate and screws, the bone still has to heal, so you are looking at six weeks for that at minimum.”

 To clarify, Ghodadra has not examined Mathews, who began rehab just four days after suffering the injury.

 Whether or not Mathews is able to return by week 1 may become a mute point in Turner’s decision to keep Brown on the roster. Fullbacks Le’Ron McClain and Jacob Hester each had two carries against the Cowboys. Turner has indicated he may use the fullback position more in the offense his season.

 “Le’Ron is an outstanding runner,” Turner said on Monday. “He is a powerful guy. He got six or eight carries today in the practice. I think he adds a physical presence to what we are doing, so I anticipate using him in that role.”

 This would make it more feasible to protect Brown on the 53-man roster. If McClain is used as a third-string RB, Turner will not need to carry a fourth RB until Mathews returns.

 Follow Chargers reporter Dan McLellan on Twitter @CBSSportsNFLSD and @sandiegosports.