Lions quarterback Matt Stafford suffered a separated shoulder in the team's 38-37 win over the Browns on Sunday afternoon. He was injured as he threw a desperation pass into the end zone, and a source told ESPN's Chris Mortensen of it's nature. "He's extremely sore today," coach Jim Schwartz said Monday. "Most of the tests have come back, and there doesn't appear to be any long-term structural damage, but there's a lot of pain. If that continues, he'd be unlikely to play on Thursday, but we're not closing the door on anything yet."