I'm not sure how it started but there was a little rumble on the field between a group of players from each team. It went down at midfield near the Steelers sideline with a group of players doing what appeared to be a lot of talking and a little bit of shoving. Coaches stepped in to break up whatever was happening down there.
The Chiefs also had a pregame rumble with the Oakland Raiders a few weeks back and promptly went out and whooped up on them. Hopefully it's a good sign of things to come.