Maryland starting strong safety Matt Robinson is out for at least three weeks with an ailing left shoulder, Coach Randy Edsall said Thursday, meaning the sophomore will miss the season opener on Sept. 1 against William & Mary.

Robinson (Atholton High School) injured the labrum in his shoudler during practice on Tuesday morning just hours before starting quarterback C.J. Brown was lost for the season with a torn ACL in his right knee in the afternoon workout.

Robinson “will be in a sling for a week, and then he’ll rehab for two weeks,” Edsall said following Thursday morning’s practice in College Park. “We’ll see where he’s at at that point in time, but it’s going to be a minimum of three weeks before he’ll get out and starting doing anything from a football-related standpoint.”

Edsall said the injury doesn’t appear to require surgery, although the second-year coach wouldn’t rule it out completely.

Robinson had surgery on his right shoulder last year that forced him to miss all but three games. Before the injury, Robinson was second in the ACC and tied for seventh nationally in tackles per game (12).

“It’s one of those things where we’ll rehab him and see how he comes along,” Edsall said.

With Robinson out, freshman Sean Davis (Maret) has been working with the staters at strong safety. Other players on the depth chart behind Robinson are walk-on Clarence Claiborne and Zach Dancel, who cannot play in games this season as a transfer from New Mexico.