Williams knows the trip to London will be a "massive test".
The 27-year-old told the Mail on Sunday: "They are a very good team and one I enjoy watching, they play good attacking football and I'm sure Spurs fans have been having a good season watching their team.
"They've had a bit of an indifferent run but they have some quality players who can hurt you. People have seen our development away from home and how we have tried to manage those periods when teams come at us.
"We are working hard all the time to try and learn from the games we've played.
"We've got a good balance away from home but this is going to be a massive test for us.
"We've worked hard for our clean sheets and we'd love to get a few more before the end of the season."