Crabtree misses practice with calf injury

SANTA CLARA, Calif. -- The San Francisco 49ers released their first injury report of the 2014 season on Wednesday and receiver Michael Crabtree, who missed more than two weeks of training camp with a hamstring issue, was the big name on it with a calf injury.

Rookie backup center Marcus Martin (knee) and right tackle Anthony Davis (hamstring) also sat out practice.

Martin suffered his injury in the 49ers’ third exhibition game, against the San Diego Chargers, and is expected to be out at least six weeks. Davis, meanwhile, is still rehabbing from offseason shoulder surgery -- he did not play in an exhibition game -- but the hamstring is a new development.