Ghana defender Daniel Opare will not return to Porto when his current loan deal at Besiktas expires.
The Turkish side are keen to snap up the Ghanaian international permanently after impressing since he joined.
Porto are demanding €2 million from Besiktas for the talented 24-year-old.
According to agreement between Porto and Besiktas, the Turks have an option to purchase and make the deal permanent at the end of the season.
Porto have already asked Besiktas to ready the amount as the season is getting close.
Opare has scored once and assisted two goals in 12 appearances for Besiktas in the current season.
Opare joined FC Porto after the 2014 FIFA World Cup campaign with Ghana but failed to make a single league appearance for the 27-time Portuguese champions due to injury.