The credibility of the Premier League has been damaged by Mick McCarthy's decision to field a weakened Wolves team against Manchester United, according to Arsenal boss Arsene Wenger.
United beat Wolves 3-0 at Old Trafford on Tuesday night after the visitors made 10 changes to the line-up that had beaten Tottenham Hotspur the previous Saturday.
McCarthy said he had rested his first-choice players to avoid them getting injured ahead of a crucial clash with newly-promoted Burnley on Sunday, but many critics saw the changes as an unfair and an admission of defeat.
Arsenal boss Wenger said: "We will have to compete with Manchester United over 37 games instead of 38. I believe it is a problem for the international credibility of the Premier League, but it is not my problem, it is a Premier League problem."
The Premier League said on Wednesday they had written to Wolves asking them for "their observations" in relation to the team that took to the field against United.
"Once the observations are received the Board will decide whether any further action is warranted," the Premier League said in a statement.
McCarthy continued to justify his selection by insisting he needed to use his full squad to cope with a busy spell of fixtures over Christmas, arguing that Wolves fans would understand his decision if they beat Burnley.
Some Wolves fans chanted "we want our money back" at Old Trafford as Wolves slipped into the bottom three.