WASHINGTON, D.C. >> A week ago at the All-Star Game, Dodgers ace Clayton Kershaw said he had been told the mild herniation in his lower back was "a non-surgical injury."But Kershaw's renewed lower back pain following a 60-pitch simulated-game session in Los Angeles on Saturday has Dodgers manager Dave Roberts acknowledging that season-ending back surgery for Kershaw is "more of a possibility" now than it was before the throwing session.