About a half hour before Sunday's AFC North showdown at Paul Brown Stadium, they proved it.
Bengals linebacker Vontaze Burfict and Steelers linebacker Vince Williams were at the center of a brief skirmish that kicked off at midfield while both teams were stretching. The skirmish was caught by television cameras from CBS, which is broadcasting the game.
The scuffle didn't last long, and it didn't appear there were any punches thrown. Both players were quickly pulled out of the fray, with James Harrison and Adam Jones serving as some of the mediators. Jones, who missed the game with a foot injury and was wearing a protective boot, stood at midfield for the remainder of the pregame warm-up period.
A Bengals source confirmed that Burfict went after Williams in part because of a series of threatening tweets that Williams posted in reference to Burfict immediately following the Bengals' win over the Steelers last month. Burfict had tackled Steelers running back Le'Veon Bell awkwardly during that game, then got up and immediately celebrated the hit. The tackle resulted in a knee injury for Bell that ultimately ended his season.
Williams was one of several Steelers who voiced their displeasure about the tackle both on social media and through reporters.