"It's inexcusable," Mayfield said, according to ESPN's Jeff Darlington. "Rivalry or not, we can't do that. That's endangering the other team. That's inexcusable. The reality is, he's going to get suspended. It's inexcusable."
Garrett tore off Steelers quarterback Mason Rudolph's helmet and struck him in the head with it as the fight unfolded, leading to the lineman's ejection.
"I don't think there's anything in that moment that I can really say to calm him down," Mayfield said, according to Michael David Smith of Pro Football Talk. "The reality is he's going to get suspended, we don't know how long, and that hurts our team. We can't do that. We can't continue to hurt this team."
Browns wide receiver Odell Beckham Jr. echoed his quarterback and believes there isn't a place in the game for that level of violence.
"As I'm seeing it now, it's really bad," Beckham said, according to NFL Network's Tom Pelissero. "It's just ugly."
Garrett is likely to be suspended for his actions during Thursday's game.