Gravesen played against his Toffees team-mate in Denmark's 3-2 win against England, and admits it is not a prospect he would relish again.
"I have seen him in games and close up, but as you saw against us he was deadly," said Gravesen.
"As soon as he sees the six-yard box he is deadly. Twice he could have killed us.
"Not only is Wayne very strong but he is clever too and he knows what to do with the ball.
"He makes the players around him better because he takes the ball and passes - and gives other players time on the ball.
"He is a player that makes other players better."
Gravesen insists that the youngster has kept his feet on the ground - despite his astronomic rise to stardom.
"I think he has taken this the right way with a cool head," added the Danish midfielder.
"He hasn't changed in my eyes. He's a clever player and he needs all the support he can get from everybody.
"I think we are quite protective of him because that gives him a breathing space in which he can be himself.
"He's a normal guy but what he is like in private is not to be discussed.
"I don't think there is a pressure on him at all because he has delivered already and is still delivering.
"Of course, as a striker you need to score goals, but he does that as well and the pressure on him is not as great as some people make it out to be.
"I am sure he will be a hit in Portugal."
