The Red Sox have confirmed that right-hander Clay Buchholz has a stress fracture of the L2 vertebra in his lower back. However, there is still a chance he could return to the mound for Boston this season and the injury is not career-threatening. "Clay has a stress fracture in his lumbar spine," Red Sox physician Tom Gill said in a statement. "He is responding to treatments and his symptoms are improving. We have sent Clay to see three spine specialists, who all agree that the injury is stable and will heal on its own. ... We absolutely expect him to be 100 percent for spring training." Buchholz will be re-evaluated after a month of rehab.