Courtois joined Chelsea back in 2011 from Genk as a 19-year-old having impressed in his native Belgium, but he's since spent the last three seasons on loan in Spain with Atletico, where he has established himself as the top young goalkeeper in the league with some stunning displays.
He's continued that into the World Cup with Belgium, but there have been plenty of questions over the 22-year-old's future at Stamford Bridge. With Petr Cech still the No. 1 in West London, there have been suggestions that Chelsea would look to sell Courtois or loan him out to Atletico again.
Yet that possibility has all but ended after Portuguese newspaper A Bola reported today that Atletico have met the release clause for Benfica stopper Oblak, which will cost €20m (£16m).
There's certainly a case to be made that whilst Courtois is the most impressive young goalkeeper around at the moment, Oblak isn't far behind. The 21-year-old Slovenian international has displaced Artur Moraes as Benfica's first choice shot stopper this season, and he hasn't looked back since.
£16m is a big outlay for someone who's played very few games, but he has impressed massively in that time and he has the potential to be one of the finest goalkeepers in Europe for the next 10-15 years - hence their willingness to pay the release clause.
Whilst Atletico have all but made Chelsea's decision for them over whether Courtois would be returning to the Spanish capital, the Blues and manager Jose Mourinho still have the big choice to make - will Courtois or Cech be the first choice shot stopper next season?