Only goalkeeper Marcus Hahnemann survived from the side that started the impressive 1-0 victory at Tottenham Hotspur on Saturday and some of Wolves' travelling fans chanted "we want our money back" near the end of a one-sided match.
NEWS: Weakened Wolves tonked at Old Trafford
Premier League Rule E20 states that clubs are required to field full-strength sides in every match but a League spokesman said it was very hard to enforce because managers often rotated their squads.
Wolves play Burnley on Sunday and McCarthy made little attempt to disguise which match he had earmarked as the most important in his side's battle to stay in the top flight.
"Having played Tottenham on Saturday and all the ratings were nine or nine and a half out of 10, every single player, and we lost a couple through cramp, and we've just got a really busy period coming up," McCarthy told BBC Radio Five.
"They were all first-team squad players who played tonight, not reserves and I have to say there were some really good performances.
"That team did as well as we did against Arsenal and Chelsea.
"Maybe I will have to have a counter-argument but that was my decision to do it. We could have got beat whatever team I put out and I might have lost somebody with a hamstring or calf strain because they were all struggling after beating Spurs.
"It was my decision and I took it and the responsibility lies with me. Burnley are having a good season and we have to be fully at it. ... I'm not prepared to get injuries before Sunday because then we have Liverpool, Manchester City and West Ham.
"I've got 20 players in my squad and I'll need all of them between now and January."
