Antonio Brown has suffered a partially torn calf muscle and will be out for at least the remainder of the regular season.
Brown caught two passes for 24 yards before he suffered the injury in the first half of Pittsburgh's loss to the Patriots.
"It changes. A.B. is significant," Mike Tomlin told reporters. "But I thought the guys did a nice job of adjusting and making plays largely. You lose somebody like A.B. and there's an adjustment."