The Dodgers' most significant acquisition in free agency walked into the clubhouse in a sling on Saturday. Tom Koehler will start the season on the disabled list, and the Dodgers reliever said he could miss weeks or months with a strain in his right shoulder. "We're optimistic he'll be back this year," Manager Dave Roberts said. Said Koehler: "I came here to help this team win a World Series. If that starts a little later in the season, so be it." Koehler was the only free-agent pitcher the Dodgers signed to a major league contract, and he had been projected as a primary setup man for closer Kenley Jansen. "He's a guy that we were counting on for high-leverage situations," Roberts said Friday. "To lose him for any extended period of time, yeah, that's a big blow." Andrew Friedman, the Dodgers' president of baseball operations, said Saturday that the injury did not make it more likely that the team would acquire a reliever via trade or free agency, in part because the timetable for Koehler's return is unclear and in part because the search for depth is ongoing. "Deals that made sense three