Rennes are reportedly putting Jean-Armel Kana-Biyik up for sale this month.
Celtic manager Ronny Deila brought in Manchester City youngster Jason Denayer on loan this summer, but he may be forced into more additions at centre back this month.
Star defender Virgil van Dijk is being monitored by about half of the Premier League, whilst Nigerian international Efe Ambrose could also leave amid interest from Leicester City and West Bromwich Albion.
Should one of them leave Celtic Park this month, Deila will need to bring in another centre back, with Ajax's Stefano Denswil linked before his move to Club Brugge earlier this week.
Yet one of Deila's reported summer targets was Rennes' Cameroonian international Jean-Armel Kana-Biyik, with reports in France suggesting that the Bhoys wanted to bring the 25-year-old to Scotland.
A deal couldn't be done though, leaving Kana-Biyik to stay in France, and he hasn't even played once this season as his exit becomes increasingly likely.
Now, Rennes are reportedly hoping to flog Kana-Biyik this month, with Ligue 1 rivals Evian believed to be leading the race for his signature.
However, when Celtic were linked with the player in August, L'Equipe suggested that Kana-Biyik had singled out Celtic as a team he wanted to sign for over other suitors such as Dinamo Moscow, Palermo and Real Betis.
If Deila still has Kana-Biyik on his radar then now would be the time to swoop for a cut-price deal, with Rennes desperate to bring in any sort of transfer fee for him to save him leaving for nothing in the summer when his contract expires.