Rennes players Yann M'vila and Chris Mavinga, sent home in disgrace from France under-21 duty for breaking a curfew, could be barred from first team duty until the end of the season, coach Frederic Antonetti warned on Wednesday.
The club ordered the pair to train with the youth squad when they reported back at the weekend and Antonetti said he was "very upset" by their behaviour.
"There's no limit on how long, quite honestly, it could go on until May 30. I haven't really taken it in yet, it's going to take some time. I'm the one who's most hurt by this, I had faith in the players."
Midfielder M'vila and defender Mavinga were dropped from Rennes' first team after spending a night out between two key under-21 European championship qualifiers and missed Saturday's 2-1 victory against champions Montpellier.
Both players were hauled in to meet club bosses and told that their behaviour had damaged the side's image before being informed they would now train with the development squad.
The sanctions come after French sports daily L'Equipe revealed that M'vila, Mavinga and three other players defied team orders and left the French under-21s' base in the northern city of Le Havre to go to a Paris nightspot.
The team had beaten Norway 1-0 the previous evening in a Euro 2013 play-off but suffered a heavy defeat at the hands of the Scandinavians 5-3 three days later. France coach Erick Mombaerts was sacked after the loss.
The two players could yet face further punishment from the French Football Federation (FFF), which has opened disciplinary proceedings against them for bringing the game into disrepute.
Antontetti said he had acted "for them and for the club" as they had to understand there were "certain things they couldn't get away with".
"I don't know whether they'll understand that," he added, "and frankly I have my doubts."
M'vila and Mavinga played in the reserves 2-0 defeat to Vitre at the weekend and Mavinga was sent off in the seventh minute for a professional foul.