Chelsea are reportedly leading the chase to sign Porto defender Nicolas Otamendi, with the Portuguese club resigned to losing him next summer.
The 25-year-old has been a central figure in the success enjoyed by Dragoes since his arrival from Velez Sarsfield in 2010.
According to Marca, the Argentine international will ignore reported interest from Barcelona and AC Milan in order to move to West London, where Jose Mourinho has identified him as a top target.
Blaugrana and the Rossoneri are thought to have had bids rejected during the summer transfer window.
Otamendi's list of honours at the Estadio do Dragao includes a league, cup and Europa League treble in his first season.
The rumours raise further questions over the future of Brazilian centre-back David Luiz, who himself has been linked with a move to the Camp Nou.
