Chicago Bears safety Chris Conte was fined $21,000 for making contact to Carolina Panthers receiver Brandon LaFell's head during their game last Sunday.
Conte told ESPN Chicago that he thought it was a practical joke.
"I didn't think it was real," he said after practice Friday. "I thought it was a prank. Then I realized it wasn't a prank very quickly. It hurts a lot."
Since Conte makes about $27,500 per game, the fine cost him nearly a week's pay. He said he will appeal the fine.
"I love football so I don't mind (the fine), but I'd like to get paid," he said. "That's a big chunk of money that I make. I think it's kind of unfair to fine a guy that's on his rookie contract that much money, but hopefully they will look at it and get it reduced."
The fine was for hitting a defenseless player in the head. Conte was also penalized on the play.
"I'm Conte's coach, so I was little surprised they called it," coach Lovie Smith said. "But they explained it and now that they explained it to us I can see why they fined him. If a guy gets penalized for something like that in a game, he'll be getting a fine next week. That's protocol."
Oakland Raiders defensive lineman Richard Seymour, New York Giants defensive lineman Chris Canty, New York Jets linebacker Marcus Dowtin and Tennessee Titans rookie defensive tackle Mike Martin were each fined $15,750, and Miami Dolphins rookie tackle Jonathan Martin $10,000 for various infractions stemming from last weekend's games.