Buffalo Bills rookie quarterback Josh Allen will not start Sunday against the Colts because of a right elbow injury, and there is concern he will miss multiple weeks, sources told ESPN's Dianna Russini.
Allen was injured in Sunday's 20-13 loss to the Houston Texans.
ESPN's Chris Mortensen reported that Allen's injury is to the ulnar collateral ligament (UCL) in his right elbow. It is not considered major at this time, but his MRI will be sent to noted orthopedist specialist Dr. James Andrews for a second opinion, which has become standard operating procedure. One of the Bills' orthopedic specialists, Dr. Leslie Bisson, completed his fellowship under Dr. Andrews.
No other specific information has been revealed, but the Bills do not want to rush him back, sources told Mortensen, to allow him to properly heal despite his competitive desire to play at less than full strength.
Bills coach Sean McDermott said Monday he and his offensive staff will "work through" whether Nathan Peterman or Derek Anderson would replace Allen.
ESPN's Mike Rodak and Chris Mortensen contributed to this report.