Sir Alex Ferguson has gone against the Football Association's guidelines not to talk about referees before matches by welcoming Howard Webb's appointment to Manchester United's match against Chelsea and speaking of his hope that "it's our turn for a little bit of luck" from the officials.

As part of the FA's Respect campaign, managers are not supposed to discuss referees in the buildup to games. However, Ferguson believes his side have been the victim of some poor decisions in their recent matches against Chelsea and was open about his concerns that it might happen again. "That's definitely our big fear, to be honest with you. Other than that, we have the players to do it all right."

Webb has awarded United a penalty in three of the past four games he has officiated at Old Trafford and Ferguson made a point of talking up the Yorkshireman. "He's definitely the best referee in the country, there's no doubt about that. We are getting the best referee and we hope it's our turn for a little bit of luck."

The United manager is still aggrieved about Martin Atkinson's performance when the sides met at Stamford Bridge in March, Chelsea coming from a goal down to win 2-1 on a night when Ferguson felt refereeing decisions had swung the game in favour of the champions.

Ferguson was subsequently banned from the touchline for five matches after castigating Atkinson in a post-match interview, saying he should never have been appointed because the occasion had demanded a "fair" referee.

"The result against us was a change for them [Chelsea]," he said. "We all know the circumstances of that game. That game gave them their lift, from being out of the game to winning it. And, of course, us losing on Sunday has opened the door for them."