Sir Alex Ferguson slated the match officials after Manchester United's 2-1 defeat by Chelsea at Old Trafford. Joe Cole put the visitors ahead but it was Didier Drogba's goal 11 minutes from time that left Ferguson fuming, with replays showing the striker was clearly offside.
The United boss told Sky Sports 1: "What I can't understand is the linesman's directly in front of it. He has no-one near him and he gets it wrong.
"A game of that magnitude, you really need quality officials and we didn't get them today. It was a poor, poor performance."
Referee Mike Dean was under pressure from last week when he awarded Blackburn a penalty against Burnley after the Rovers player later admitted he dived.
United had two penalty appeals turned down today while Chelsea also looked to have a good shout when Gary Neville barged Nicolas Anelka.
Asked whether Dean had been affected by the comments, Ferguson added: "I don't know about that but when I saw Mike Dean I did worry, I must admit."
Chelsea now lead United by two points with five games to go, and Ferguson put the pressure on his rivals by making them firm favourites.
"Five games left, they're two points ahead and four goals better than us - they're in the driving seat," he continued.
"Chelsea are favourites now, there's no question. I'm certain we'll respond but we could win the next five games and not win it."
United looked to be suffering a hangover from the midweek Champions League quarter-final defeat against Bayern Munich.
Ferguson said: "The first half we looked leggy, it took us too long to get going and Chelsea were by far the better team.
"The second half we did well, we were unfortunate not to get something from the game. We dominated it in the second period but we just didn't get there.".
