Chelsea interim coach Frank Lampard criticised his team's lack of fight and said he has to turn around the club's slump urgently before Tuesday's visit by Real Madrid, following the Blues' latest limp defeat.
Lampard, speaking after a 2-1 home Premier League loss to Brighton & Hove Albion, said Chelsea -- the 2021 Champions League winners who are now stuck in 11th place in the Premier League -- were displaying a worrying failure to perform the basics of the game.
"Disappointing on every level," he told Sky Sports. "The better team won and could have won by more. They played like a team. They're working together for a long time, give that credit.
"But it's not good enough from our point of view. All the basic parts of football -- to fight, to run, and those things -- we were short on. We have to dig ourselves out of that very quickly.
"We've got a big game on Tuesday. There's no point in being too down, but professionally we have to understand why today went the way it did. And it wasn't good for us."
Lampard said the defeat to Brighton was the most disappointing performance of the three games since his return to Stamford Bridge to see out what looks like being a barren first full season under Chelsea's new American owners, despite their huge outlay on new players.
Asked if he wanted to urge Chelsea fans to energise the team on Tuesday against Real Madrid -- with the Spaniards 2-0 up from the first leg of the quarterfinal - Lampard said the focus had to be on the players, not the support from the crowd.
"I know they will do that but we have to play with that energy and fight, that's like the bare minimum," he told media in a news conference. "That's up to us, in terms of the game on Tuesday."
Brighton coach Roberto De Zerbi, who took over the Seagulls when Potter departed the south coast for his short and fruitless stint at Chelsea and is now on course to guide them into Europe next season for the first time, praised the way his players dominated the Blues.
But he also said he was unhappy at the way Brighton allowed Chelsea a couple of late chances to equalise.
"When we scored the second goal we thought only to finish the game, to spend time," he said. "And I spoke after the game to my players about this. If we want to become bigger we have to improve in this aspect."
The Italian said he believed his side could book a place in the FA Cup final by beating Manchester United in next weekend's semi-final of the knockout competition.
"It will be another difficult game, it's another big team. Man United I think are one of the best teams in the Premier League but I think we are able to win and I think able to fight," he said.
Information from Reuters was used in this report.