Chelsea announced plans on Monday to appoint a new manager within days, after Portuguese media linked Porto's Andre Villas-Boas with the Premier League club.
Portugal's national news agency Lusa and several Portuguese newspaper websites reported that Chelsea has agreed to pay the 15 million ($21.5 million) release clause in Villas-Boas's Porto contract.
"We hope to be able to make an announcement regarding the new manager in the next few days," Chelsea said in a statement responding to questions about Villas-Boas.
Porto said it has "received no information that the clause will be activated nor the coach's willingness for it to happen."
But Porto President Jorge Pinto da Costa said he would be powerless to prevent the 33-year-old Villas-Boas leaving if the price is met to release him from a contract that runs until 2013.
"If someone puts 15 million into our bank account and he wants to leave, there's nothing we can do about it because that's the contractual undertaking," Pinto da Costa told Portugal's Sport TV. "If that doesn't happen, he won't leave."
Villas-Boas would be replacing Italian Carlo Ancelotti, who was fired last month after his second season at Chelsea ended without a trophy.
And at 33, the Portuguese is the same age as Chelsea players Frank Lampard and Didier Drogba who he worked with at Stamford Bridge under compatriot Jose Mourinho.
Comparisons with Mourinho were reinforced last month when Villas-Boas emulated his compatriot by winning the same European competition that launched the career of the self-styled "Special One."
Villas-Boas became the youngest coach to win a UEFA club competition when Porto's unbeaten season ended with a victory in the Europa League final, eight years after Mourinho won the competition in its UEFA Cup incarnation.
After Mourinho, who now coaches Real Madrid, moved from Porto to Chelsea in 2004 he won back-to-back Premier League titles.
Villas-Boas was a scout for Mourinho at Chelsea and followed him in 2008 to Inter Milan.
Villas-Boas, who speaks fluent English, had also worked with Bobby Robson during the English coach's spell at Porto's Stadium of the Dragon. He coached the British Virgin Isles at just 21.
Porto ended the past season unbeaten in the domestic championship with 27 wins in 30 matches. In Europe, it recorded 14 wins in 17 games, scoring 44 goals with an attacking style of play favored by Villas-Boas.
Porto became only the second Portuguese club to finish a league season unbeaten, after Benfica's 1972-73 team.
"I don't approach football with only a tactical approach - you can achieve success through various means. What I like is to make my players give their most but I give them lots of room to maneuver," Villas-Boas said on the eve of the Europa League final. "I try to promote their talent and feel free to make the right decisions. I'm no dictator."