The Blues are likely to push for the Spain international in the summer.
The 27-year-old has made 20 Premier League appearances so far this season in which he has kept 7 clean sheets.
Manchester United are looking to sign a new stopper in the summer and Raya is a name high up the wishlist. Tottenham Hotspur are also said to have interest.
Raya, who is contracted to the Bees until 2024 – could be available for around £25million considering his current market value.