Marseille president Vincent Labrune has said goalkeeper Steve Mandanda will not be leaving the club this January.
Mandanda, 30, is out of contract in the summer, and both Besiktas and Aston Villa are said to be keen on signing the France international.
Labrune also said he expected top scorer Michy Batshuayi and full-back Benjamin Mendy to extend their contracts.
Mandanda is also reported to be interesting Liverpool, Newcastle, Norwich and Roma, who have all been credited with an interest in recent weeks.
The goalkeeper has spent the past eight years at Marseille and, speaking to RMC on Tuesday, Labrune insisted he would be going nowhere this winter.
The president said a gentlemen's agreement between the pair to allow Mandanda to leave should a suitable offer come in had only applied to recent summers.
"We're not going to part with our best elements and our key players in the middle of the season," Labrune added.
"Mandanda is one of our driving forces, and he won't leave this winter. We're both on the same wavelength. We don't want to sell him, and Steve is not looking for a club."
If Mandanda does stay, RMC reported that a clause in his contract stipulates that it will be automatically extended should Marseille qualify for the Champions League.
The club are currently 10th in Ligue 1 -- meaning that, if they do not improve considerably, the keeper would be free to leave in the summer.
Meanwhile, Labrune said he thought Batshuayi, a reported Crystal Palace target, would sign an improved contract deal in the coming days, with left-back Mendy, 21, also tipped to extend his current agreement.