London - Under-fire Maurizio Sarri admitted his Chelsea flops played "confused" football as they crashed out of the FA Cup with a tame 2-0 defeat against Manchester United on Monday.
Sarri was subjected to calls for his sacking from angry Chelsea fans during the troubled team's fifth defeat in their last 10 games.
Booed off at the final whistle, the beleaguered Blues manager felt Chelsea deserved better after the FA Cup holders started the fifth round clash on top.
But he conceded they lacked direction and focus in a tepid second half surrender.
"Tonight we were unlucky because we played a very good first half and at the end of the half the score was 2-0," Sarri 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."
Toothless Chelsea managed only two shots on target all night and the limp second half display suggested the players are hardly doing everything in their power to save Sarri.
Sarri has publicly criticised his squad on several occasions in his first season in charge, questioning their mentality and motivation.
The former Napoli is now in danger of being axed by ruthless owner Roman Abramovich, with Thursday's Europa League tie against Malmo and Sunday's League Cup final against Manchester City looming as must-win matches if Sarri is to save his job.
"I feel the pressure for results of course, not about something else," he said when asked if he was concerned about being sacked.
"We have to work, we have to speak, we have to find more aggression and determination in both boxes."
United's commanding display was the perfect way to bounce back after last week's disappointing Champions League last 16 first leg loss to Paris Saint Germain.
Ole Gunnar Solskjaer was delighted with the way his players responded to that setback and United's interim manager was especially impressed with their work-rate.
"The performance tonight was fantastic, our tactics worked. We asked our midfielders to press higher and get into the box and it worked," Solskjaer said.
"Chelsea are a good team, they have their way of playing but Juan Mata did a fantastic job on Jorginho and we were absolutely perfect defensively. We kept a clean sheet.
"It is a massive result. We had criticism after the PSG game and everyone did what we asked them tonight."