Chargers linebacker Shawne Merriman has returned to San Diego after receiving second and third opinions regarding his torn knee ligament, according to ESPN.com. Doctors told Merriman that he could suffer a career-ending injury if he plays without undergoing surgery. If he does decide to have surgery, the timetable for his return is not yet known. He could miss just a few weeks, or the entire season. "I've been seeing some really great doctors over the past few days and they've all said the same things about the injury," Merriman said. "[They're] kind of surprised that I've been playing with it up to this point."