Courtois is currently on loan at Atletico Madrid and has frequently been linked with a move to Barcelona, but Mourinho has insisted that he wants to retain the services of someone he describes as "the best young goalkeeper in the world".
The 50-year-old told reporters: "We have the best goalkeeper in the world and the best young goalkeeper in the world. It's a very good problem. Our goal is safe and financially we are also very safe - the value in the market is the value of the best.
"In this moment, I don't think about it. It doesn't worry me because our situation is fantastic and everything is under our control. We control the situation, not Barcelona, Atletico or another team interested in our goalkeepers. We control the situation so that's fine."
The 21-year-old, who has yet to feature for Chelsea, has made 110 appearances during a prolonged loan spell at the La Liga side.