In recent months, Ronaldo has been strongly linked with an exit from the Bernabeu, with speculation coinciding with Real's struggles in La Liga.
Reports have suggested that Ronaldo would welcome a return to Old Trafford - where he enjoyed a successful spell between 2003 and 2009 - but Mourinho has insisted that United will not be signing the Portuguese star.
At a press conference, the 54-year-old told reporters: "I think with the moment Real Madrid is having now I think I should be the last one to add some fuel to the fire. Madrid is on fire, the results are not good and it's a club where I worked three years, I cared about the club, I am the last one to add [to the] fire.
"To put some water on the fire, I would say Cristiano is the kind of player that everyone wants, but only one manager can have and only one club can have – [Zinedine] Zidane and Real Madrid. That's my feeling."