Unai Emery has a release clause of just £5.3million amid strong interest from Aston Villa in the former Arsenal manager.
The Spaniard is currently in charge of Villarreal in his homeland, and led them to Europa League glory in 2021, and the Champions League semi-finals last season.
Villa sacked Steven Gerrard last Thursday and have targeted Emery after intermediaries had also made contact with Mauricio Pochettino, Thomas Frank and Ruben Amorim.
It is understood Emery, whose contract expires at the end of the season, can be effectively bought out of his contract for less than £6m – a far lower fee than required by Sporting Lisbon for Amorim.
Villa are attracted to Emery because of his top European pedigree, his knowledge of the Premier League and his familiarity with the 4-2-3-1 system.
There is a feeling at Villa that this formation is best suited to the players they have, and caretaker-boss Aaron Danks used it to great effect against Brentford on Sunday, with Villa winning 4-0. Under Gerrard, Villa rarely set up this way, using 4-3-3 or 4-3-2-1, or occasionally a midfield diamond.
Were Villa to pay the clause, it would then be for Emery to decide whether he wants to return to the Premier League, where he was sacked by Arsenal in 2019 after a little more than a season in charge.
One year ago, Emery appeared set to join Newcastle, only to have a change of heart and stay in La Liga.
He has a large degree of control at Villarreal and it remains to be seen whether he would have similar influence at Villa, where sporting director Johan Lange and chief executive Christian Purslow also wield considerable power.
But billionaire owners Nassef Sawiris and Wes Edens are determined to restore Villa to the elite of English football and would be prepared to back Emery with significant funds in the January transfer window.