Chelsea have spoken out amidst the speculation and the UEFA press release. Can their goalkeeper, on loan at Atletico Madrid, play against them?
Short answer - yes.
Chelsea chief executive Ron Gourlay, who was present at the official draw for the UEFA Champions League semifinal in Nyon, Switzerland earlier today, Friday, explained that, as a club, they are law-abiding, that they would process the official UEFA statement in due course but that they have a agreement with their final four opponents Atletico Madrid regarding the loan status of hot Belgium shot-stopper Thibaut Courtois, 21, and that, if they choose to, they are free to play him.
"The loan was arranged at the start of the season," said Gourlay to Sky Sports.
"Thibaut can play against Chelsea, that was never in doubt," he added.
"And regarding the UEFA statement that came out, we'll evaluate that in due course but as far as we're concerned we abide by rules et-cetera. As far as the player is concerned he can play against Chelsea in both ties if selected by Atletico Madrid."
Courtois has featured 31 times for Atletico in La Liga, making 56 saves and keeping his sheet clean 17 times. In the Champions League he is under more pressure from European attacks but, in nine outings, has made 23 saves.
Earlier, La Liga expert Guillem Balague explained that he had spoken with Atletico and that they may not choose to select Courtois against Chelsea as, if they did, it could sour their relationship with the London club and spoil their chances of extending the player's loan spell for an additional season.