Denayer joined Galatasaray on loan from City over the summer transfer window and has already established himself as a key member of the team.
“We have the option to loan Denayer for another season but that will come down to an agreement between all three parties involved,” Ergün told Fanatik.
Galatasaray also have the option to sign Denayer on a permanent transfer. The Lions have a £30 million release clause which will remain active until the end of the season.
“It will not be easy to transfer Jason we have a £30 million release clause which we would struggle to match under the current circumstances,” he added.
The Belgium international has one assist in five games in all competitions for the Lions and has already become a fan favourite.
Denayer is expected to start for Galatasaray against Benfica in the Champions League on Wednesday. The Lions are currently last in the group with one point from their last two games.
Galatasaray are currently second in Turkish Super League two points behind league leaders Beşiktaş.