Martinez knows a win can take the Toffees four points clear of their opponents and potentially back into a Champions League berth.
He said: "Spurs are one of the teams in form. Since the new manager has come in, they play with a real freedom.
I think they have got rid of that responsibility and tension of having a lot of money spent in the summer - I think it's the opposite now.
"They have a very good group of players trying to enjoy their football. They come out in games expressing themselves.
"I feel that they are a difficult side to face now and it's going to be a terrific test."