The former Aston Villa player went to ground easily for a penalty during United's goalless draw with Real Sociedad in Spain.
While Young has faced criticism for his antics, Moyes believes that the focus should be on the match referee who awarded the penalty, which was not converted by the Premier League champions.
"The referee was two yards away from it," Moyes said in a press conference. "If anything you should be more talking about the referee than the player. He also refereed the Champions League final so you are expecting him to be as qualified as anybody.
"The question should be 'did the referee get the decision right or not'? For me, where I was, I definitely thought it was a penalty."
Reports have claimed that Moyes is considering selling Young.