CLEVELAND -- Cleveland Browns rookie quarterback Johnny Manziel was fined $12,000 by the National Football League on Friday for his obscene gesture after an eight-yard touchdown pass in Monday night's 24-23 loss to the Washington Redskins at FedEx Field.

Manziel tossed the obscene gesture toward the Washington sideline.

"I get words exchanged with me throughout the entirety of the game, every game, week after week, and I should've been smarter," Manziel said after the game. "It's a Monday Night Football game, and the cameras were probably solidly on me, so I need to be smarter about that. There's always words exchanged on the football field.

"Since my name has grown bigger and people have known who I am, it just continues to go as the games continue on. I don't know if there's a single level of severity each game, but I know it's there, and it's present every game. I've just got to let it slide off my back and go to the next play. I felt I did a good job of holding my composure throughout the night, and you have a lapse in judgment and you slip up."

Following the game, first-year Browns coach Mike Pettine said he "was surprised" by the actions of Manziel, whom he named the No. 2 quarterback behind veteran Brian Hoyer on Wednesday morning.

"That does not sit well," Pettine said. "I was informed of it after the game, and it's disappointing because what we talk about is being poised and being focused. You have to be able to maintain your poise. That's a big part of it.

"All football players, especially the quarterback, we have to keep our composure. That's something that we'll obviously address with him. That's why I was surprised when I heard about it because other than that, I thought he was composed."

Pro Bowl cornerback Joe Haden said he "wouldn't have" given Washington's bench an obscene gesture as Manziel did, but understood why there was a desire to express his frustration with the way the Redskins' players and fans treated the first-year signal-caller.

In his postgame press conference, Haden declined to repeat the comments directed at Manziel because he could not say them on air.

"If you stand on our sideline, it's so bad," Haden said. "The whole time we were there, everybody was just talking the worst things you could ever imagine. I was next to him a lot of times on the sideline. He gets a lot of grief, but you've just got to try and not listen to it.

"That's from everybody, their bench, their fans, everybody. There's a lot going on. There's a lot of pressure on him, and just people talking. It could get a little overwhelming.

"Manziel, he's a very, very popular player. He gets a lot of attention. He gets a lot of people to just scream out things that are very, very disrespectful. You've just got to act like you're zoning it out."