Reece James felt Chelsea took "a step back" after suggesting they "disrespected" the Europa Conference League during their quarter-final second-leg defeat by Legia Warszawa.

The Blues progressed to the semi-finals of the competition, in which they are the favourites to lift the trophy, after a 4-2 aggregate victory.

However, Enzo Maresca's side were thankful for doing the damage with a 3-0 victory in the first leg, as they went down 2-1 during a disappointing second leg at Stamford Bridge on Thursday.

Despite advancing to the last four, Chelsea were booed by several sections of the supporters, with the result on the night doing little to ease the pressure on the Italian head coach.

James empathised with the Blues' faithful, insisting he and his team-mates could have "no excuses" for their performance.

"We advanced in the competition, but it was a poor performance from the team," the Chelsea skipper said.

"The game was always going to be different. It's the second leg, away from home, they have nothing to lose, and they showed that. They made it tough for us, and we didn't step up.

"We had a 3-0 lead. Maybe that played a part in taking our foot off the gas, but there are no excuses. We are making progress, but that was not progress. If anything, it was a step back.

"Maybe we disrespected the competition. If you don't prepare right, you will pay.

"It's going to affect the mindset. It's going to be in the back of people's heads. I understand the frustration. Fans come to see excitement, but we were frustrating to watch."

Chelsea suffered their first defeat in this season's Europa Conference League, having won each of their opening nine matches.

And Maresca felt the Blues were more disrespectful towards their opponents, than the competition itself.

"Probably, not the competition, but probably the other team, because I think we respect the competition all season," he said.

"Probably tonight, because of the first result, you can manage the [second] result in the wrong way. We are in the semi-final, but at the same time, we were probably trying to manage after the result of the first leg."

The form of Chelsea's attacking players is also providing a cause for concern, with left-back Marc Cucurella their top scorer in all competitions since December 15 with six goals.

Cole Palmer has now gone 15 matches without a goal, while Nicolas Jackson and Christopher Nkunku have failed to find the net in 12 and eight games respectively.

Jadon Sancho also only ended a 21-match goal drought by scoring against Ipswich Town on Sunday, and Maresca hopes it is a situation that will soon be addressed.

"We are missing very easy goals," he conceded. "Hopefully, very soon, Nico and Cole can start to score goals, because they are very important for us.

"The one scoring at the moment is Cucurella. That is not a good thing because he is not the one to score the goals."