Guardiola's side have lost eight of their past 11 games in all competitions following the devastating 2-1 defeat in the Manchester derby at the Etihad Stadium on Sunday.
Manchester City have won just once in 11 games in all competitions, a run that includes eight defeats.
Enzo Maresca's high-flying Chelsea beat Brentford 2-1 at Stamford Bridge to close to within two points of long-time leaders Liverpool, who have 36 points.
Josko Gvardiol's first-half goal appeared to have won the game for the Premier League champions but Bruno Fernandes levelled from the penalty spot in the 88th minute and the impressive Amad Diallo poked home the winner two minutes later.
Guardiola's side have won once in their last 10 matches in all competitions, sit fourth in the Premier League, eight points behind leaders Liverpool, and are in danger of a humiliating exit from the Champions League.
However, profits dipped from £80.4 million in City's treble-winning 2022-23 campaign to £73.8 million last season.
Manchester City were plunged further into crisis on Wednesday after falling to a 2-0 defeat at Juventus which threatens their chances of reaching the last 16.
The English champions stand accused of 80 breaches of financial rules between 2009 and 2018, plus a further 35 of failing to cooperate with a Premier League investigation.
Manchester City are fourth in the league table on 27 points after 15 games, while Palace are 16th.
The 24-year-old Argentina international's exit marks a record sale price for City, eclipsing the 50 million pounds Chelsea paid for winger Raheem Sterling in 2022.
City won the trophy for the first time since 2019.
Coach Erik ten Hag insisted last season could have turned out very differently had injuries not hindered Manchester United's progress, but further setbacks ahead of the new campaign have dampened the mood around Old Trafford once again.
The 24-year-old cost City just £14 million when he signed from River Plate in January 2022 and his since enjoyed a meteoric rise, helping Argentina to World Cup and Copa America glory, as well as winning two Premier League titles and the Champions League at club level.
Reigning Premier League champion City scored goals 54 seconds apart in the first half and 71 seconds apart in the second half to dominate the fixture, part of a US pre-season tour for both clubs.
Manchester City have been fined more than 2 million pounds ($2.56 million) by the Premier League for delayed kickoffs and restarts, England's top flight league said on Wednesday.
De Bruyne has just one year left on his current City contract and the midfielder revealed recently he has spoken with his wife Michele about his future plans.
The Belgium captain has six Premier League crowns and one Champions League title, as well as two FA Cups and five League Cups to his name since his 2015 switch from German side VfL Wolfsburg.
Erik ten Hag warned Manchester United's owners that he will carry on winning trophies elsewhere if they decide to sack him in the aftermath of Saturday's 2-1 victory against Manchester City in the FA Cup final.
The Spanish coach has previously won the award four times since he joined the club in 2016. With six league titles, he is now the joint second-most successful coach in the history of English football.
