The former Madrid midfielder has spoken highly of the Spanish club's coach, saying he has fond memories of their relationship and valued the Portuguese tactician's opinion
The former Spain Under-21 international left Los Blancos during the summer transfer window to sign a four-year deal at the west London club.
And Granero feels he has learned a lot while at the Santiago Bernabeu which will hold him in good stead in the future.
"He [Mourinho] has always wanted what's best for me," the 25-year-old told Marca. "He didn't want me to leave, but he understood.
"He wished me the best, he gave me good advice and he helped with my decisions. I have good memories of him.
"He told me I was going to be happy, and I thought so too. His opinion was important.
"We exchange the odd message and I think a lot of him. He's taught me a lot.
"He's a great manager and he treated me well."
The midfielder also spoke about his time with new club QPR, who currently lie bottom of the Premier League after taking three points from their opening nine games.
"I'm very happy," said Granero. "So far, the results haven't been the best, but they will be. It's going to be a very good season.
"All I want is for time to pass slowly because I'm happy," he added.