Man Utd were unhappy Mike Riley did not give a penalty after Danny Welbeck went down in the box
Manchester United manager Sir Alex Ferguson said comments from Everton's David Moyes may have denied the Red Devils an FA Cup semi-final penalty.
Referee Mike Riley did not give United a spot-kick when Danny Welbeck appeared to be fouled by Phil Jagielka and Everton went on to win on penalties.
Everton boss David Moyes had queried the choice of Riley prior to the game.
Ferguson said: "I've no idea if it affected the decision but it may have. It can prey on a referee's mind."
I thought it looked a penalty kick
Everton manager David Moyes
Riley's decision prompted Ferguson to storm angrily towards the pitch but in his post-match media conference the United boss admitted there had been room for doubt over the decision.
"I've seen the video and it looks a penalty kick but in the importance of the game the referee probably has to be dead sure," added Ferguson.
"Why would Welbeck go down when he had the goalkeeper stranded out of his goal? It was a major decision and unfortunately it has gone against us. Nothing you can do about it. We have to move on now.
Ferguson confronts fourth official Alan Wiley over Riley decision
"When Riley sees it he'll probably realise he's made a mistake but I can't say that's the reason for us losing."
United captain Rio Ferdinand supported Ferguson's suggestion that referees are hesitating over giving the champions penalty decisions.
"We don't get many penalties these days," stated Ferdinand. "Referees are reluctant to give them to us. Maybe they're are being put under pressure by people in the media."
Moyes had questioned the choice of Riley after it had been suggested he was a United supporter.
Riley was appointed to referee the match at Wembley after original choice Steve Bennett withdrew because of illness.
In January, Liverpool manager Rafael Benitez had claimed that Ferguson is "the only manager who will not be punished" for verbally attacking referees, a comment which has sparked an ongoing feud between the two managers.
However, Moyes conceded that United had been unlucky not to have been given the penalty.
"I thought it looked a penalty kick," said Moyes. "If I had been the manager I would have been calling for a penalty kick."
Moyes was too nervous to watch Jagielka score the decisive penalty as Everton won the shoot-out 4-2 to reach the FA Cup final for the first time in 14 years.
"I'm really, really pleased. I'm pleased for myself and the team but, more importantly, the supporters. They were fantastic," Moyes told BBC Radio Five Live.
"I have got to praise Manchester United because they gave us a real hard game. I know on another day they could have put another team out and it could have been even harder.
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