Aston Villa manager Alex McLeish revealed that Charles N'Zogbia was left out of the squad to face Manchester United on Saturday due to a disciplinary breach.
The Scot said that the winger failed to turn up for treatment on a injury before the side's 1-0 defeat at Villa Park.
"Charles never turned up to treatment on one of the days last week when we was supposed to so he's got to take it on the chin and he has to show us the great player he can be," said McLeish.
"There's been good performances but I'm looking for people who pick up the gauntlet and say, 'you're going to find it hard to leave me out next week'.
"But, in saying that, it was a discipline matter and that would have been the case for anybody, there's no favouritism and when it comes to something like that we have to respect the rules. There'll be an internal [investigation]."
The loss has left the West Midlands club ninth in the Premier League table.