Nick Bosa is relentless on the football field. He is a force to be reckoned with and is sure to start making opposing quarterbacks feel uneasy as they head into games.

When you speak with him off the field, you get a very different person. At least, Bosa is different than you might expect. The defender is very reserved. He'll answer your questions but typically isn't one to talk smack or call out someone.

That's why his father, John Bosa, a former NFL defensive end himself, was so surprised when he saw his son perform the flag-plant celebration to troll Cleveland Browns quarterback Baker Mayfield on Monday night. While amusing, it was out of character for the defender.

"That was very out of character, actually," John Bosa told Greg Papa and John Lunch on KNBR this week. "And that will probably not be the norm for him. He had some extra motivation. He will bring that same fire every Sunday, or every Monday or Thursday. That, you'll never have to worry about. He'll have the same fire. He just had a little bit of extra (motivation).

"I think maybe the opposition's quarterback (Baker Mayfield) maybe got under his skin a little bit as far as some of the way he carries himself, and I think that might have been perceived as a little bit of disrespect. But that was kind of out of character."

John went on to share that both of his sons are very low-key, soft-spoken, respectful, and humble. Sometimes, people are taken aback when they meet the two NFL defenders for the first time because it's not what they imagine after watching the Bosa brothers play on the football field.

"I'm proud of the way they handle themselves," John continued. "Nick had a little fun with it after the game, and it was truly all in good fun."

Fans, of course, loved the celebration from Bosa and the display of enthusiasm from the young defender. It's that type of energy that will be embraced by the fans at Levi's Stadium doing forward, especially if it comes with a performance like the one on display Monday night.

Bosa's celebration was a response to an incident a couple of years ago when Mayfield, then with Oklahoma, planted a Sooners flag into a logo on Ohio State's home field after an upset victory over Bosa's Buckeyes.

How did the Browns quarterback feel about the taunt?

"Bosa, good for him," Mayfield said this week. "He had it premeditated. He's been thinking about that, obviously, for two years now, so that's a long time to think about that loss."

You can listen to the entire conversation with John Bosa below.