The Lions are optimistic Stafford's thumb injury isn't serious, Ian Rapoport of NFL Network reports.
After X-rays came back negative, he'll have more tests Monday to make sure there's no structural damage. The Lions don't expect him to miss any games, but it's possible the outlook changes if the tests reveal something significant. Stafford was sharp in Sunday's 30-27 win over Washington, completing 24 of 33 passes for 276 yards. Next up is a road matchup with the Panthers on Sunday afternoon.