Former Celtic striker Kris Commons does not think striker Odsonne Edouard will push for a move away from the club.
But fans are worried he may follow in the footsteps of Moussa Dembele, who eventually left for Lyon.
The former Hoops star told the Daily Mail: "One theory which I've heard doing the rounds in recent days has been that Odsonne Edouard's future will hinge on Celtic's progress in Europe this season and what happens over these next few weeks.
"The suggestion seems to be that a failure to reach the group stage of the Champions League would inevitably hasten his departure prior to the transfer window closing in October.
"I totally disagree with that. For me, there's absolutely no chance that Celtic will even contemplate selling their star striker at this late juncture. That ship has sailed.
"The season is already under way. If they were of a mind to cash-in on Edouard, they'd have done it six weeks ago to give themselves time to find a suitable replacement.
"The signing of Albian Ajeti changes nothing in that respect. Despite the £5 million ($6.5m) fee, there's no way he's been bought as a direct replacement for Edouard. You don't replace one of the best young strikers in Europe with a boy who was warming the bench for West Ham last season."