Manziel reportedly has not decided whether he will appeal the fine.
With the Redskins trailing 14-3 in the third quarter, Manziel raised his middle finger toward Washington's bench after throwing an incomplete pass.
Manziel addressed his action after the game.
"I just need to let it slide off my back and go to the next play,'' Manziel said, according to The Plain Dealer in Cleveland. "I felt like I did a good job of holding my composure throughout the night and you have a lapse of judgment and slip up."
Manziel completed 7 of 16 passes for 65 yards in the game.
Asked Tuesday whether Manziel's gesture would factor into the decision on the Browns' starting quarterback, coach Mike Pettine said, "We'll take into [account] all things QB from A to Z'.'
- Chris Johnson