Chelsea are reportedly prepared ‘to pay Jan Oblak’s £89million release clause’ in order to replace Thibaut Courtois before the start of the season.Courtois failed to turn up for training on Monday and has told the club he wants to move to Real Madrid, leaving Chelsea with little time to sign a new goalkeeper before the transfer window shuts on Thursday evening. According to a report in Mundo Deportivo though, the Blues are set to raid Courtois’ former club Atletico Madrid for their star man Jan Oblak. The Slovenian stopper has an £89m release clause, but the Spanish paper writes that Chelsea will pay that in the next 24 hours as they look to push through the move. It is understood that the Stamford Bridge outfit have turned to Oblak after moves for Alisson, Pepe Reina and Jordan Pickford fell through this summer.Their three ‘more affordable’ options fell through after Alisson chose instead to move to Liverpool, while Reina opted to remain loyal to AC Milan, who have just paid £9m to sign him. Everton, meanwhile, asked for £58m for Pickford, but Chelsea have now opted to spend more to ensure the arrival of one of the world’s best goalkeepers. Oblak’s potential arrival in west London would likely ensure Courtois gets his way and secures a return to the Spanish capital, where his family live. He spent three seasons on loan at Atletico Madrid after joining Chelsea back in 2011, impressing as the club won La Liga and the Europa League, before finishing runners up in the Champions League in 2014.