The Blues are again in the market for a new manager - their fifth in the past three years - as Carlo Ancelotti paid the price for a trophyless campaign just 12 months after guiding his team to a historic double.
Staying put: Villas-Boas will ignore Chelsea's advances and stay at Porto, according to the club's president
While Guus Hiddink is said to be Roman Abramovich's first choice to reprise the role he filled on a temporary basis to such great effect two years ago, convincing the Dutchman to leave his current post with the Turkish Football Federation could prove complicated.
Villas-Boas, 33, would be no stranger to Stamford Bridge, having worked there under Jose Mourinho.
Despite the Portuguese coach having seen his stock rise after guiding the Dragons to domestic and Europa League success, president Da Costa sees no reason for concern over his future.
Up in the air: The 33-year-old led Porto to a domestic and Europa League double this season
Speaking to Portugal's public service broadcaster PTP, Da Costa said: 'I do not expect the exit of Villas-Boas - there is a clause price of 15million euros but I am totally convinced that even if any club came in with the offer, he would reject the proposition.
'Villas-Boas is very committed to Porto and more so after this big season.
'Two days ago he also told me that if no players leave, then he will not even need any new players.'
In the hat: Mourinho (left) and Hiddink are among the contenders to take the managerial reigns at Chelsea
Villas-Boas is on the four-man managerial short-list under serious consideration by at Chelsea.
It includes an outsider - 40-year-old Russian rookie coach Leonid Slutsky of CSKA Moscow, a club with whom Abramovich has strong ties.
But Guus Hiddink remains the favourite to replac Ancelotti at Stamford Bridge and has declared an interest in winning another European Cup by returning to club management.
Jose Mourinho is also on the list, although he may not yet be ready to return from Real Madrid where he still wants to conquer mighty Barcelona in the Spanish league.
Hiddink poised for Chelsea return as Dutchman now heads Abramovich wish-list Ferguson scoops Manager of the Year award. and then lauds axed Ancelotti One last pint, then goodbye. Carlo pays for trying to please AbramovichMourinho hints at Chelsea snub as Special One eyes future with Madrid Explore more:People: Roman Abramovich, Jose Mourinho, Carlo Ancelotti Places: Madrid, Barcelona, Portugal