Williams plots to stop RVP
The Netherlands international has netted 12 times in 17 Premier League appearances this season and Williams is relishing the challenge of marking Van Persie, highlighting the need to stop the service to the ex-Arsenal man.
"Van Persie's on fire at the minute and playing with a lot of confidence so we just have to work to stop him and stop the service into him," Williams told the Daily Express.
"There's no doubt he's going to get a couple of chances, that's just the way it goes against a quality team, but we have to dominate possession and starve them.
"He's one of the best strikers in the Premier League, if not the best. Technically he's very good and you can all see his goalscoring abilities.
"He's a complete player and was one of the best I played against last season. You watch Manchester United so many times so you know what they're all about. But trying to stop them is a different thing altogether."
Williams believes the Swans showed Sir Alex Ferguson's side too much respect when they lost 1-0 in last season's match at the Liberty Stadium, but believes they can get a positive result this time around.
He added: "It is true that we showed United too much respect last season. We sat back too much in that first half and then got at them.
"We deserved a draw at least. Scott Sinclair missed a chance, an open goal, and they had one chance.
"But this season we've got a lot more belief. We don't fear anyone. We're at home and we've lost two on the bounce so it would be great going into Christmas to get a positive result."