Thibaut Courtois will NOT play against his parent club Chelsea in the Champions League semi-final, according to reports in Spain. The Blues will take on Atletico Madrid later this month for a place in the final in Lisbon in May. And according to Marca, the Belgian stopper won't go up against his parent club - as Diego Simeone wants to keep him on loan next season. Courtois has been a major reason for Atletico's rise this season, and was again in outstanding form as Los Rojiblancos saw off Barcelona in their quarter-final clash this week. Now he could stand in the way of his parent club, after UEFA declared that any clause denying him the opportunity to play in the semi-final was “null, void and unenforceable” . Publicly Chelsea have stated that they are prepared for the young keeper to play, with chief executive Ron Gourlay stating: “As far as the player is concerned, Thibaut, he can play against Chelsea, in both ties, if he is selected...That is fact.” But behind the scenes they are known to be furious that the clause inserted in Courtois' deal in the Spanish capital at the start of his third loan spell has been overruled by UEFA.