Donovan McNabb was carted off the field with a right knee injury early in the second quarter of Philadelphia's game against the Tennessee Titans on Sunday. McNabb was rolling to his right near the Tennessee sideline and was bumped out of bounds by Kyle Vanden Bosch after throwing an incomplete pass. He grabbed his leg and was immediately tended to by trainers. There was no immediate word on the extent of his injury, but the team said he wouldn't return. He was replaced in the lineup by Jeff Garcia.