DK Metcalf got into an altercation with a Lions fan in the second quarter:

Metcalf was not available for an interview after the game. He left the locker room before the media was allowed in. 

Mike Tomlin’s only comments on the incident didn’t reveal much more than that, either.

“I heard about it, but I hadn’t seen it and I hadn’t had an opportunity to talk to DK,” he said. “So, I have no comment.”

The NFL will review the incident. The most recent precedent for how the league might handle this goes back to September this season when a fan slapped Lamar Jackson’s helmet and he retaliated by shoving the fan. The fan was ejected and banned from the stadium. Jackson was not punished by the league.

We still don’t know what the fan might have done or said to prompt the response from Metcalf.