Manchester City manager Pep Guardiola says his team must improve before the Champions League final if they want to lay their hands to a trophy they dream to land at the Etihad.
City blew up a two goal advantage to lose 3-2to Brighton in a match played out in front of 7,495 fans.
Ilkay Gundogan silenced the supporters when he opened the scores after two minutes but they had to play with ten men for most of the game when Joao Cancelo was sent off for a foul on Danny Welbeck.
Phil Foden's superb solo effort in the second half put the visitors 2-0 up - but Leandro Trossard gave Brighton hope with a well taken goal to half the deficit.
Adam Webster levelled for the Seagulls, rising above the rest to head home a Pascal Gross corner with Dan Burn scoring the third to send the home fans in raptures.
"Eleven against 11 against Brighton is tough, 11 against 10 is difficult so we have to improve for the final," said Guardiola after the match.
"Unfortunately after 0-2, we conceded a goal so quick and after they push a lot, we were more tired and could not keep the ball as much as possible - we could not do it and unfortunately we lost the game.
"On Sunday, with our people, we are going to lift the [Premier League] trophy. And after we are going to go for the final of the Champions League.
"I am concerned because this is the final of the Champions League, because the opponent is so tough."
City also lost Gundogan to injury in the second half, but Guardiola provided positive news about the midfielder after the game.
"We are going to check tomorrow," said the manager of the German, who had earlier scored his 17th goal of the season.
"The doctor is quite optimistic. The problem is a kick and he was running in the second half with disruption and I didn't want to take a risk."