The Spanish leaders take on CSKA Moscow on Wednesday with the tie delicately poised following a 1-1 first leg draw at Luzhniki Stadium in Russia.
The pressure is on Mourinho to deliver European success having won the prestigious trophy with Inter Milan in 2010 following a 2-0 success over Bayern Munich at the Santiago Bernabeu.
Real are currently ten points clear of Barcelona in the race for the Liga title and Mourinho, who has been linked with a summer return to Chelsea, does not think failure against CSKA will affect his position.
"My future won't be decided by Wednesday's result, unless the club fire me if we don't qualify," said Mourinho. "But from my point of view it (result) won't change a thing.
"The first leg was a complicated result which leaves things quite open. Looking to Wednesday I'm more afraid of the game, which can produce all sorts of surprises."