The Premier League is to ask Wolverhampton Wanderers why they fielded a reserve side against Manchester United on Tuesday night.
Manager Mick McCarthy decided to make 10 changes to the side which beat Tottenham Hotspur at the weekend, resulting in a 3-0 defeat at Old Trafford.
The Premier League said in a statement: “The Premier League Board have written to Wolverhampton Wanderers to request their observations in relation to the team fielded in their League fixture against Manchester United.
“Once the observations are received the Board will decide whether any further action is warranted.”
McCarthy has defended his decision, saying he wanted to save his players for the weekend meeting with Burnley at Molineux.
McCarthy told the club’s official website: “It wasn’t always in my mind to make so many changes but it was a decision I made after Saturday’s game at Tottenham. The players give their own ratings on how difficult they felt the match was fitness-wise and the average was nine-and-a-half to ten.
“We have to be at that level to get anything out of a match and it just wasn’t going to happen on Saturday and Tuesday and then on Sunday again. And we’d lost Dave Edwards on top of Keogh and Kightly to operations. We couldn’t have done it again and then again on Sunday.
“I read an article somehow where (Chelsea manager) Carlo Ancelotti had said that the risk of injury in one game is 10%. And then that goes up to 30% or 40% if another intensive game follows in three or four days. We believe that anyway, but that came from the Milan Lab research centre set up by AC Milan.
“That was the best team available to me because it was fresh legs and I thought we were as competitive as we were against Chelsea and Arsenal.
“I can understand why people might not be too happy. But I’ve got a squad of players to pick from and they are all first team players. I hope supporters can understand why but it’s my job to make those decisions. If we do stay up then maybe everyone will look back and say they were all good decisions.
“It’s my job to keep this club in the Premier League and I’m making decisions which I believe are right. I took the decision knowing full well the questions that would be asked and what has happened that we’ve come out without any more injuries.
“I’m here to look after this club and I make decisions which I believe are for the good of this club.”
Wolves chief executive Jez Moxey has backed his manager.
“We have a squad system at the club and Mick picked what he thought was the best side for that match.” he told Sky Sports News. “In fact if George Friend had taken the chance he had early in the game then maybe we could have held on just like we did at Tottenham.”
Moxey also said the club had no plans to refund fans who travelled to the game.
“We have no plans to refund the £42 that they were chanting about, although we do have an empathy with them,” he said. “We are very disappointed that we lost the game, but we have a squad system.
“I don’t think we are going to get any complaints from other teams. We have also had a large amount of injuries recently, Michael Kightly is out and we have lost Andy Keogh. It’s an old saying but the season is a marathon not a sprint and Mick’s job is to keep us in the Premier League.”