Alvaro Pereira's agent has confirmed Porto and Chelsea are in discussions over a big-money deadline day transfer, although nothing has been agreed.
Blues boss Andre Villas-Boas knows all about the Uruguay international from his time at Estadio do Dragao and wants to be reunited with the 25-year-old prior to the transfer window closing.
Chelsea have already seen one bid rejected and the Stamford Bridge outfit are hopeful of avoiding having to pay the lofty €30million (£26m) required to activate Pereira's release clause.
The former CFR Cluj and Argentinos Juniors man is now waiting to hear whether a fee can be agreed and his agent Alejandro Savich is currently in England on stand-by hoping to seal a deal.
The likes of Barcelona, AC Milan and Inter Milan have also been mentioned as possible suitors, however, Pereira's lack of an EU passport means he is unlikely to join those European giants.
"I know that the clubs are talking. This is a positive sign. What I know from Chelsea is that they are trying. One can only hope," Savich told Maisfutebol.
"It's a lie to suggest he has ever refused to play for FC Porto or taken some action. You know that Alvaro always gave everything. He's played more than one hundred games. This cannot be questioned.
"Right now, Alvaro Pereira is waiting while the clubs talk. We have not spoken with Chelsea because I'm not allowed to do so. It is essential Porto and Chelsea reach an agreement first.
"Alvaro has enough international appearances for Uruguay to play in England. But the fact that he doesn't have an EU passport compromises the interest of Barcelona, AC Milan and Inter Milan."
Porto were interested in signing Blues' new signing Romelu Lukaku on loan, but the Belgian striker cannot play for a third club this season having already featured for Anderlecht.