London - Jose Mourinho admitted Michael Oliver's decision to send off Ander Herrera had ruined Manchester United's chances of beating Chelsea in Monday's explosive FA Cup quarter-final.
Mourinho's side were beaten 1-0 at Stamford Bridge after United midfielder Herrera was dismissed in the first half for two fouls on Chelsea star Eden Hazard.
Herrera's second challenge on Hazard made only the slightest contact and, while Mourinho stopped short of openly criticising Oliver, he did his best to make clear his frustration at the decision.
"Everybody can analyse from different perspectives but we all watch the match until the red card and after the red card," he said.
"So we can compare the decisions of the two yellow cards, in this case with others which were not given.
"I don't want to go in that direction. Michael Oliver is a referee with fantastic potential but in four matches he has given three penalties and a red card (against United).
"I cannot change that. I shook his hand and said many congratulations."
Chelsea manager Antonio Conte was furious with United's rough treatment of Hazard, who was subjected to several tough tackles in the first half and was stamped on by Marcos Rojo in the second half.
Conte had to be pulled away from Mourinho on the touchline at one stage and he had no doubts Oliver was right to send off Herrera.
"I think Hazard started the game and couldn't play. All the people look at this and then judge," he said.
"It was a good performance against a strong team with good players. United has the best squad in the league.
"For us we must be pleased to go into the next round."
Chelsea defender Gary Cahill accused United of targeting Hazard, saying: "We complained as we thought they were going in on Eden.
"The red card turned it in our favour. There were fouls leading up to that so it was possibly silly (for Herrera) to go in like that."