Uefa has told Chelsea manager Jose Mourinho to stop criticising referees.
Mourinho became embroiled in a row after intimating that referee Anders Frisk favoured Barcelona in the first leg of their Champions League tie.
Uefa spokesman William Gaillard has now said: "He can say many things but frankly to get into this area of refereeing is counter-productive.
"Let's stop casting more doubt on the honesty of Anders Frisk, who is an outstanding referee."
Gaillard continued: "I don't think it is very helpful to keep on critcising the work of a referee like Frisk.
"He has had an outstanding career, has taken many courageous decisions, often in front of hostile crowds.
"To suggest he influenced the game in Barcelona is an unacceptable comment."
And Gaillard said he wanted to concentrate on the second leg of the tie at Stamford Bridge, which will be refereed by Pierluigi Collina.
"It's time to shut up and get on with the game between two great coaches in what should be a fantastic match," added Gaillard.
Mourinho had come in for criticism on Monday after European football's governing body suggested that the Chelsea coach had tried to influence their decision of referee for the second leg.
The Chelsea coach was alleged to have said he knew Collina would be handed the second-leg tie and a Uefa spokesman told him to stay out of its business.
"We didn't really appreciate Jose Mourinho saying at the beginning of the week that we had assured Chelsea that Collina would be refereeing the game. It is not true," said Gaillard.
"He was trying to put pressure on us. We had decided to appoint Pierluigi Collina even before we considered the incidents but his comments made it very difficult for us to do so.
"He should stop picking out which referees he likes and which he doesn't like."
But Mourinho responded to those comments, saying at a news conference on Monday evening: "It is a shame that an institution the size and importance of Uefa has misinterpreted what I said.
"I didn't ask for Collina to referee. What they said was completely untrue."