Speaking to the BBC after the match, Sarri claimedChelseawere unfortunate to lose but needed to be more aggressive.
"Tonight we were unlucky because we played a very good first half and at the end of the half the score was 2-0," he said.
"We gave them a few opportunities. We played confusing football in the second half.
"After the first half it wasn't easy to play with that score. We played very good first half.
Maurizio Sarri says Chelsea played "confusing football" (Image: EPA)
Maurizio Sarri felt Chelsea were unlucky (Image: PA)
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"I feel the pressure for results of course, not about something else.
"We have to work, we have to speak, we have to find more aggression and determination in both boxes."
Pedro started the match but failed to impose himself on the Manchester United defence.
But he has called on people to remain calm despite their “difficult situation”.
Chelsea boss Maurizio Sarri looked worried on the touchline (Image: ACTION)
He said: "It was a big opportunity for us to stay with the supporters but now it is a difficult situation. A difficult day for us.
"In the second half it was so difficult for us. Now the most important thing is to stay calm and prepare for the final on Sunday and the Europa League.
"We have to believe in ourselves and this team, we have great players."