Vince Wilfork has been handed a $30,000 (£18,500) fine for unnecessary roughness in the New England Patriots' game against the Jacksonville Jaguars last week.
The defensive lineman struck Steve Vallos in the head with his forearm in last Sunday's fixture.
After the game, Wilfork said that he had been sticking up for a teammate when he committed the foul.
However, teammate Patrick Chung has escaped a fine despite drawing a penalty flag for a hit on Cecil Shorts in the same game.