Manager Roberto Mancini has warned his players they are risking their ability to play a full part in Manchester City's busy programme if they ignore repeated warnings over their drinking.
Reports - accompanied by grainy footage - have emerged suggesting that City quartet Adam Johnson, Gareth Barry, Joe Hart and Shay Given were involved in late-night partying on a trip to Scotland earlier this week.
"I have not seen this video but I told them my opinion about this situation 10 days ago," Mancini said.
"I don't understand this. The video was on Monday, and Monday was a day off. Some players can do what they want, but I don't understand why.
"I am unhappy about this, but for them. We play every three days and it is difficult to recover. I want to resolve this problem in the dressing room, not here (in a press conference)."
He added: "I think this problem is not only for us, it is for many players. For British players, it is part of the culture."