The NFL suspended Williams indefinitely Wednesday for his part in the bounty program operated while he was defensive coordinator of the New Orleans Saints.
Fisher, who had been anticipating the suspension for a couple of days, said he had no inclination anything like this would happen when Williams was hired as the new Rams defensive coordinator.
Despite the blow of losing a top assistant going into his first year as Rams coach, Fisher said he agreed with the NFL's punishments, which also included a one-year suspension for Saints head coach Sean Payton.
"Not a good day for the National Football League," Fisher said at an afternoon press conference.
Williams will now rely on NFL commissioner Roger Goodell to determine whether or not he is reinstated and, if so, on what terms.
"He's remorseful," Fisher said of Williams, "and he regrets the decisions he made. He accepts the consequences."
Goodell issued a memo telling every NFL team it must certify that no such bounty program exists. The certification is to be presented in writing by each principal owner and head coach by March 30.