Ngata was one of several players fined that amount by NFL on Friday for rough hits.
Washington linebackers Rob Jackson and Perry Riley were disciplined for their play in Sunday's against St. Louis. Jackson was fined for driving Rams quarterback Sam Bradford to the ground. Perry was docked for striking a defenseless player fielding a punt.
Also, Oakland defensive lineman Richard Seymour has been fined $7,500 for each of two hits. The first was for unnecessarily driving New England quarterback Tom Brady to the ground, and the second for a facemask penalty against running back BenJarvus Green-Ellis.