Donovan McNabb is unlikely to play in Philadelphia's game against the New York Giants on Sunday because of a groin injury. "I wouldn't bet on it," Eagles coach Andy Reid said Tuesday when asked if McNabb could start. "He doesn't look good today." McNabb injured his groin while trying to tackle Dallas' Roy Williams after throwing an interception. Williams returned the pick 46 yards for a touchdown with 2:43 left to lead the Cowboys to a 21-20 comeback victory over the Eagles on Monday night. Reid said McNabb had an MRI on Tuesday morning, and was waiting to see a specialist. If McNabb doesn't play, Mike McMahon probably would start against the Giants. McMahon, listed as the third-string quarterback, played the last series against Dallas, and drove the Eagles to the Cowboys 42 before David Akers missed a 60-yard field goal attempt in the final seconds. McNabb has played through several injuries this season, including a sports hernia that will require surgery. He walked gingerly to the podium at his post-game new conference and grimaced with every step. Reid said McNabb is "sore more in the groin area than in the abdominal area."