Nantes are likely to lose the three points they earned with their opening-day defeat of Bastia after the newly-promoted side fielded an ineligible player.
Back in the top flight for the first time since 2009, the 2000-01 Ligue 1 champions celebrated their return with a 2-0 win against the Corsicans. However, the emergence of 19-year-old trainee Abdoulaye Toure from the bench with 23 minutes left may cost them dear.
The teenager should not have even been in the match-day squad having picked up three bookings in less then ten competitive fixtures for the club's Under-19 and reserve teams late last season, synonymous with a one-game suspension which should have been served last weekend.
Though the French Football League (LFP) has yet to adjudicate on the matter, the gaffe, which apparently stems from an oversight by club employees who should keep track of players' disciplinary status via dedicated software, will set the team back in its battle to remain in France's top division.
"It's a big disappointment for the players who really gave their all on the pitch. We find ourselves with no points as the kid was suspended and we didn't know. We did what was necessary on the pitch, but administratively, we got it all wrong," coach Michel Der Zakarian said.
"It's a huge blow. We had nothing to do with it, what else is there to say? We simply have to live with it," left-sided defender Olivier Veigneau added. "At the start, we struggled to come to terms with it. Nobody understands how it could have happened. Of course we're annoyed, but we're not going to go around hitting people."
Nantes have the scant consolation that regulations mean Bastia, who initially did not spot the error themselves before finally lodging a complaint, will not get the points instead.
"I need to analyse it. There are people who look after these matters and who handle all these problems, and they've gone on holiday," club president Waldemar Kita explained to RMC. "Don't panic."