"We'll see," McDermott said. "We're continuing to go through the medical evaluation on that."
McDermott added Monday that he received the "good news" that X-rays on McCoy's injured right ankle were negative. McDermott otherwise declined to detail the extent of McCoy's injury.
If McCoy cannot play, the Bills have only two healthy running backs on their roster: Mike Tolbert and Marcus Murphy. Activated from the practice squad last week, Murphy ran seven times for 41 yards in the Bills' 22-16 win Sunday over the Miami Dolphins. Tolbert ran seven times for 39 yards.
McDermott said Monday that he and general manager Brandon Beane have "ongoing" conversations about whether to add a running back to the roster.
McCoy was carted off the field after injuring his ankle in the third quarter of Sunday's playoff-clinching win over Miami. He did not return to the game.