Speaking about the Keane factor, Williams said today: "We all know about Roy Keane the player.
"He had an incredible career and he has not just been there and got the t-shirt - he has the hat, the scarf, the badge and just about everything that goes with it - he has the lot.
"Sunderland are a massive club and expectations are high, but you have to be certain of one thing.
"That is that everybody loves beating Roy because of who he is and what he achieved in the game.
"That will be no different on Saturday against Villa and I am sure Martin O'Neill will be looking to get one over on Roy."
He added: "I think the home games are really important and you need to register three points almost every time you go out at the Stadium of Light.
"It can be a daunting place for opponents and that is what Sunderland need to continue doing.
"The Christmas period is massively important and every team will be involved in the scrap.
"It has been proved down the years if you do well in the festive games it gives you a good chance."