Maierhofer has made just two starts and seven substitute appearances since moving to Molineux from Rapid Vienna last summer.
He cannot understand why McCarthy has been so reluctant to give him a chance, especially with Wolves the lowest scorers in the Premier League this season.
The 27-year-old admits the whole experience has left him feeling infuriated as well as confused.
"I don't have a clue why I've not been in the team. I work hard in training, yet others get to play," Maierhofer said in the Daily Star.
"Why have Wolves signed me only to not use me? Kevin Doyle cost £6.5million, so he has to play yet he has just got six goals in 25 games, which is not a great deal.
"The manager told me I lacked match practice after my operation.
"Then Andy Keogh came back from a three-month lay-off, trained for two days and then played against Bolton and Manchester United.
"I feel like they are taking the p*** out of me."
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