Saints captain Jose Fonte wants the Southampton board to honour a gentleman's agreement to leave the south coast this summer, according to The Times' Duncan Castles.
It has been reported that when Fonte signed a new three-year deal last year, it was verbally agreed upon that the club would not stand in the defender's way if he was subject of a bid from a club that he was keen to move to.
Now, it is understood that the defender is subject from bids from Everton as well as clubs in Serie A with Jose Mourinho also interested in his compatriot.
Speculation has intensified over the past few days that Mourinho would like to sign the Euro 2016 winner to bolster is defensive options ahead of a title-challenging campaign.
Castles has also reported that Fonte has been left angered at the fact that Southampton failed to inform him of a £9m bid he was subject to from former manager Ronald Koeman at Everton.
Although not formally agreed upon in his contract like a release clause would be, a gentleman's agreement would mean that if Fonte was keen on a move, then the Southampton board wouldn't step in his way.
A gentleman's agreement is understood to have been used after Morgan Schneiderlin's initial transfer request was refused two summers ago after subjected to bids from Tottenham.