Porto have told 'Chelsea they must pay £40million' for left-back Alex Telles as Frank Lampard looks to shore up his side's leaky backline.
The 27-year-old Brazilian has been a key target for the Blues, who have made several attempts to sign him from the Portuguese club.
But they will need to trigger his £40million release clause that Porto officials are sticking to, according to A Bola.
It comes as defender Marcus Alonso is rumoured to be looking for a route back to Italy with Inter Milan.
The Spaniard has been with the west Londoners since 2016 after signing for £23million from Fiorentina.
And out of favour full back Emerson's future is also in doubt.
But Chelsea may have to battle the likes of PSG, Ajax and Juventus for Telles, with the Italian giants reportedly offering £21million for the defender.
Leicester are also rumoured to be making a move as a scout was believed to have been sent to Portugal by the Foxes.
Telles is out of contract at the end of the next season and Porto do not want to lose him on a free transfer.
The left-back has signalled his intent to leave this summer by rejecting the offer of a lucrative contract extension.
He has been a regular in the Porto side this season, making 32 appearances and scoring eight goals.