Oakland Raiders running back Michael Bush, who earned the starting job in training camp, said on his Twitter account Tuesday that he had surgery on his left thumb to repair a fracture.
Bush, who gave no time frame for his return, had screws inserted into the joint Monday, according to the *Contra Costa Times*.
The third-year pro, who started seven games last season, rushed for 589 yards and three touchdowns on 123 carries. He added 17 receptions for 105 yards.