The Portuguese tactician led the Portuguese giants to a domestic double last season while also winning the Europa League following a 1-0 win over league rivals Braga.
Inter Milan reportedly made an enquiry for his services over the weekend but are said to have baulked at the £13.2 million release fee Villas-Boas has inserted into his contract.
That leaves Chelsea in pole position, with fresh speculation in Portugal suggesting that the Blues' owner Roman Abramovich is willing to meet Porto’s demands and make Villas-Boas their first signing of the summer.
Porto's president, Pinta da Costa, admits he will be powerless to stop the 33-year-old moving to Chelsea should they meet the asking price.
"Villas Boas has a contract and a clause of €15 million,” Da Costa told Portuguese newspaper Record.
"If someone deposits €15 million into our account and he wants to go, we can not do anything because it is something that is contractually specified."
Chelsea have been on the lookout for a new manager since the sacking of Carlo Ancelotti at the end of last season.
Turkey coach Guus Hiddink has been the bookies' favourites to take over in recent weeks but reports now suggest that the Dutchman, who won the FA Cup while in temporary charge of Chelsea in 2009, will become Director of Football, leaving Villas-Boas to take charge of the first team on a day-to-day basis.
By Ben McAleer
