Bailly joined Marseille on loan last summer from Manchester United and was impressive at the start of the season.
However, injuries and suspension have affected his campaign and he put in a disastrous performance in Marseille’s 3-0 defeat at home to Paris Saint-Germain last month.
Since then he has not started a Ligue 1 game for the French giants and there are suggestions Marseille are trying to avoid the scenario where the defender triggers the obligatory purchase clause in the loan agreement.
Marseille would be obliged to buy the centre-back from Manchester United if he plays 50 per cent of the matches.
However, Courbis stressed that it is difficult for Tudor to build a team with Bailly given his injury problems, disciplinary record and inconsistent performances.
The former Marseille coach told French daily La Provence: “Given his fragility, Tudor cannot count on him regularly.
“He must build something solid over the long-term with parts that are not known to be the most reliable in the market.”
It remains to be seen what the future holds for Bailly, with new Manchester United boss Erik ten Hag having hit upon a winning formula.
