However, Mourinho stressed that Rooney is Manchester United's player at the moment and that he was not very comfortable speaking about the matter.
Rooney's future has been the subject of much speculation this summer, although new United boss David Moyes is adamant that he is not for sale.
The England man, who has had to leave United's pre-season tour due to a hamstring injury, has yet to publicly state that he is happy to remain at Old Trafford, and Chelsea are one of the clubs he has been linked with.
And, speaking at the start of their Thailand tour, Mourinho said: "It's a tricky question because I cannot speak about players from other teams.
"But you know me, it's not my kind of character to speak with a bit of hypocrisy and I always say what I think.
"He is a player I like very much but I can say no more than that. Being fast and direct, I like that, but he's a Manchester United player."
Moyes, also in Thailand for Manchester United's pre-season tour, was told about Mourinho's comments. Asked if he felt the Chelsea boss was being mischievous, he said: "I don't think so.
"People are entitled to talk about good players. I am being asked plenty about Wayne so I am sure Jose will be getting asked about lots of players as well.
"It is hard to keep repeating myself - but I will do. Wayne is a Manchester United player and will remain that."
Experience means a lot
Mourinho meanwhile said is happy to be back at Chelsea and thinks he is an even more effective manager than when he departed back in 2007.
"I think I am better now, because my job is the kind of job where experience means a lot," he said.
"After Chelsea I went around Europe and had two years in Italy, three years in Spain, so I have more football culture than I did before.
"So, I think I am in better condition than before. Some more white hairs, in my case, is a good sign, because it shows I learn more.
"Until the first defeat comes, I am happy. But it is up to my team to help me, support me and try to get good results for the club."