The Blues had two bids for Rooney rejected in the summer and there has been speculation Mourinho is ready to pounce and take advantage to snare the England striker if United fail to qualify for the Champions League at the end of the season.
Asked about Rooney, who is entering the final 18 months of his contract at Old Trafford, Mourinho shook his head and insisted he was not prepared to speak about a player from a team Chelsea are scheduled to face at Stamford Bridge a week on Sunday.
"I don't want to speak about it," Mourinho said.
"We play Man United in a few days. I don't think it's nice to speak about a Man United player.
"You have to ask him (Rooney). You have to ask the player. And Man United because Man United has a contract with the player that doesn't end at the end of the season."
Mourinho does not anticipate United will struggle to finish in the top four, despite David Moyes' men being five points adrift in seventh with 18 games left this season.
"I don't think they have a problem," the Chelsea boss added.
"In this moment they are not top four in the Premier League, but they can be at the end of the season.
"A new manager, but a club with a fantastic culture of supporting the manager.
"I don't feel any problem for David. He works. Better results will arrive and he will be for many years in the club and will reach good results."