Pittsburgh Steelers defensive end Brett Keisel suffered a left tricep injury in the third quarter of the Sunday game against the New Orleans Saints and his return is doubtful.
Keisel was in obvious pain when he left the field.
The Steelers had already lost cornerback Brice McCain to a hamstring injury in the first quarter.
The Saints currently lead the Steelers 28-13 heading into the fourth quarter.
With Keisel out, rookie Stephon Tuitt will see more playing time.
Update: Keisel had been downgraded to out.