The Blues shot stopper was initially linked with a move to Premier League rivals Liverpool earlier this month before the Reds completed a £4.7m deal to sign Loris Karius on Tuesday afternoon.
Courtois has now emerged as a target for La Liga giants Real Madrid after reports suggested that their long-term target David De Gea is set to stay at Manchester United ahead of the appointment of Jose Mourinho.
The 24-year-old kept just five clean sheets in an injury-hit season, with Asmir Begovic deputising for the Belgium international for much of the 2015/16 Premier League campaign.
However, Courtois, who returned from a three-year loan spell at Atletico Madrid in 2014, has provided a cryptic update on his future at the west London club ahead of Antonio Conte’s arrival this summer.
“It has been a difficult season,” Courtois is quoted as saying by Daily Mirror. “I was injured and when I returned I did not play well, my level was lower than the season before.
“Finishing 10th is not good for Chelsea.”
Courtois won the Premier League in his first season as Chelsea number one.
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