Thibaut Courtois
Chelsea want Karl Darlow should Courtois stay at Atletico Madrid. [Reuters]

Chelsea are reportedly close to completing the signing of Nottingham Forest goalkeeper Karl Darlow, as manager Jose Mourinho is considering letting Thibaut Courtois stay at Atletico Madrid one more season.

Recent reports claimed that the Portuguese boss is preparing a huge overhaul in the summer following Chelsea's 1-0 defeat against Crystal Palace.

And having already signed midfielder Nemanja Matic, winger Mohamed Salah and centre-back Kurt Zouma during the January transfer window, his main summer target is to bolster the squad with a top striker.

Nevertheless, according to Spanish newspaper AS his first summer signing may be 23-year-old keeper Darlow, who has made 39 appearances in the Championship so far this season, keeping 11 clean sheets in the process.

AS reports that the Blues are close to finalising a deal for the Forest number one as back-up for Petr Cech next season.

The Spanish newspaper suggests that Mourinho is ready to part with 41-year-old Mark Schwarzer and will allow Courtois to spend another season at Atletico, as the Belgian doesn't want to come back to West London without the guarantee of a starting place.

Chelsea are now willing to let Courtois stay in La Liga if he agrees to renew his current contract at Stamford Bridge, which expires in 2016. Mourinho believes that he will be the perfect long-term replacement for 31-year-old Cech.

Even though some reports claimed last month that Courtois will join Real Madrid once his contract at Chelsea expires, he has said that his future can only lie at Stamford Bridge or the Vicente Calderon.

"The only thing I've always said is: that it is Atletico Madrid or Chelsea. I love being at Atleti, I want to play and if I can't do that at Chelsea, and can carry on here, I'd be very happy," he said.

"I want to concentrate on Atleti. I've never spoken with Mourinho. Chelsea can't tell me now if I'll be their keeper, because Cech is playing well, and he's one of the best keepers in the world. I'll let you know my decision; I'm going to announce it soon. For now, I'm just focused on the games we have left."