Mourinho has a contract with Madrid until 2016 but there was been widespread speculation in the media that the Portuguese will call time on his three-year stint with the Spanish giants this summer.
However, Galatasaray playmaker Sneijder, who was at Inter when Mourinho decided in the wake of their Champions League final victory in 2010 to swap the Italian outfit for Madrid, has not been swayed by reports that the 50-year-old seems certain to leave.
He told Marca: "Listen, there are things about Mourinho in the press every day which don't necessarily need to be true. I don't know if he's going to leave to be honest. In my personal opinion, it would seem very strange to me that he would leave already, so quickly.
"The work that Mourinho's doing at Real Madrid is perfect.
"He won the league last season, they've always gone far in the Champions League, this season they are still fighting to win it. I think his job is there, isn't it?"
Sneijder was speaking ahead of Wednesday's Champions League quarter-final first leg between Galatasaray and Madrid in Spain.
That match will see Sneijder return to the Bernabeu, where he had a mixed time as a player during two seasons with Madrid between 2007 and 2009 before helping Inter lift the Champions League there under Mourinho.
The Holland international said of this week's match: "It's very special, for many reasons.
"On a personal level, it's a very emotional game and, as a professional, it's a lovely game.
"I still have several friends there and I've got incredible memories with the team and the fans.
"My first season in Madrid was very good, we had a great team and personally I enjoyed playing a lot. The other season was bad for personal problems. The second year wasn't easy for me, but this doesn't take away the fact I have a good memory of Real Madrid."
Sneijder, who described Mourinho as like a second father to him, is now hoping to help dump his former club out of Europe, although he concedes it will not be easy.
"We'll go to the Bernabeu with the belief that we can do well. We know that it will be a very difficult and complicated game, but we have a good side. I believe in my team and as long as we don't lose confidence, we will make something of this tie," he said.
"In the Champions League you never know. Fifteen bad minutes and you could say goodbye to the competition.
"You need be focused 100 per cent for the whole 180 minutes, especially if you are facing an opponent like Real Madrid.
"For us it's very important to go into the game in Istanbul with a real chance of getting through. If we manage to get back here with the tie still open, it could be incredible. Our fans always give us a lot of support and anything could happen. "