New Chelsea boss Antonio Conte has been searching for a new centre back all summer, but seen moves for Juventus’ Leonardo Bonucci, Roma’s Kostas Manolas and Napoli’s £50 million valued Kalidou Koulibaly all fail – or prices rise to above what Chelsea want to pay.
Sweden international Lindelof, 25, made a big impression in his first season with the Portuguese giants, and would be a much cheaper option.
Lindelof is a versatile defender and can play centrally, as a right-back or holding midfielder.
He has six caps for Sweden and was part of Janne Andersson’s squad for Euro 2016.
Conte has meanwhile also won his battle to bring in his own goalkeeping coach to Chelsea.
Gianluca Spinelli, who worked with him with the Italian national side, comes in, assisted by Henrique Hilario. Current long serving goalkeeper coach Christophe Lollichon will move to another role.