Athletic Bilbao are in negotiations with PSG over the potential summer signing of left-back Yuri Berchiche.
The 28-year-old made 32 appearances in all competitions for the Ligue 1 champions last season, scoring twice and providing five assists.
Athletic are now keen to acquire his signature, as they look for defensive reinforcements in the summer transfer market.
While PSG are reluctant to sell Berchiche, who has previously played for the likes of Real Sociedad and SD Eibar, manager Thomas Tuchel has now given the green light to the transfer.
Athletic and Berchiche have an agreement over personal terms, with both clubs locked in negotiations over a fee for the Spaniard.
PSG are keen to receive more than €20 million (£17.5m/$23m) for the player although Athletic are working to lower that asking price, in the knowledge that PSG must comply with Financial Fair Play regulations.
The French club are understood to be obliged to raise €60m (£53m/$70m), and the sale of Berchiche would contribute a significant amount to that total.