Courtois, 21, first made his name as a 16-year-old with Genk, and made over 40 appearances for the Belgian club before his impressive displays were noticed by Chelsea, who paid a reported €6m to land the starlet. With Petr Cech firmly entrenched as the Blues' first choice shot stopper, it made sense to loan Courtois out and that's just what they did upon his signature, sending him to Atletico on an initial one-year loan deal.
Yet the Belgian's superb displays in the Spanish capital have resulted in that loan being extended each year, and now Courtois is considered one of the finest goalkeepers in European football, with a big World Cup campaign expected for him this summer.
The question still remains though. Where will Courtois be playing his football next season?
There have been plenty of rumours about the situation; Courtois returning to Chelsea and replacing Cech, being loaned out to Atletico again or even being sold to another team, but his performance against the Blues in the recent Champions League semi-final could have sealed his fate.
Today's speculation suggests that Mourinho saw enough in that game to want the Belgian back in West London next season, and will hold face to face talks with Courtois this summer in a bid to plead with him to stay - despite his desire to be the starting shot stopper wherever he plays next season.
Cech is still only 31 and appears to have a number of years left at the top of the game, but in Courtois, they have someone just as good yet 10 years younger. It may be a tough choice to make for Mourinho, but if he's serious about keeping Courtois at Stamford Bridge, he may have to make him his first choice.