"The Premier League Board has written to Wolverhampton Wanderers to request their observations in relation to the team fielded in their League fixture against Manchester United," the statement read.
"Once the observations are received the Board will decide whether any further action is warranted."
Wolves manager Mick McCarthy, whose team face fellow strugglers Burnley on Sunday, selected a virtual second-string line-up for the Old Trafford defeat which put them back in the relegation zone.
"I took the decision knowing full well that questions would be asked and was has happened is that we've come out tonight without any more injuries," McCarthy was quoted as saying on the club website.
Only goalkeeper Marcus Hahnemann survived from the side which recorded a surprise 1-0 victory at Tottenham Hotspur last weekend leading some Wolves fans to chant "we want our money back" during the United match.
The defeat dropped Wolves back to 18th in the league, above West Ham United and Portsmouth, with 16 points from 17 games, while United drew level on 37 points with leaders Chelsea.
"I read an article somewhere how (Chelsea manager) Carlo Ancelotti had said that the risk of injury in one game is 10 percent," McCarthy said.
"And then that goes up to 30 or 40 percent if another intensive game follows in three or four days. We believe that anyway..."
"That was the best team available to me tonight because it was fresh legs and I thought we were as competitive tonight as we were against Chelsea and Arsenal."
Premier League Rule E20 states that clubs are required to field full-strength sides in every match but a League spokesman said on Tuesday it was very hard to enforce because managers often rotated their squads.
