The match is expected to see new Wolves manager Vitor Pereira in the away dugout.
Van Nistelrooy said this morning: "Of course you can do some research on what he has been doing in Saudi, how he has been playing in teams he has managed before. Also we can have a good look at what Wolves have been doing over the last month but of course there can be changes made.
"Will it be big change or minor? These are all questions that we have to face and prepare for. We also have to be prepared for some surprises."
On injuries, Van Nistelrooy also said: "Harry (Winks) this week was fully part of team training so he is available for selection again which is very positive news for the squad. Wilfred (Ndidi) is in his rehab, he is not on the pitch so he is not available for selection."
On goalkeeper Mads Hermansen making the game, he added: "That is the question, we are still doing everything we can, Mads as well to make it for the game.
"It is a possibility that he can, that is the good news. It was worrying he had to leave the pitch at half-time. It was immediate assessment and treatment and rehab going on over the week so far. We are waiting to see how today and tomorrow go to see if he can play on Sunday."
He added, "We know where we are in the table and Wolves as well and the situation they are in and we are in. For us it is important to continue developing.
"It's more than where we are in the table and where the opponent it. It is the next step in development in the way we want to play and act and also the reaction to the defeat."