Mourinho said: "Many names are being talked about and they could all be a help for us.
"If in the end it is Ruud then I would be very happy. We know each other from English football, in my first seasons (at Chelsea), I know the player and the person well. I would be delighted if it is him."
Mourinho added of the prolific forward, who this evening scored Hamburg's winner against Schalke in the Bundesliga: "At the moment he is a Hamburg player and we need to respect that situation.
"I don't want to talk of Van Nistelrooy. For you (the media) it's easy. I have to respect Hamburg."