City remain on course for an unprecedented quadruple of trophies.
Real's task appeared to have been made much easier after Atalanta's Remo Freuler was sent off in the 17th minute.
Guardiola's men hold a five-point lead at the top of the table with a game in hand over second-placed Manchester United.
Yaya Toure has been named assistant manager of Olimpik Donetsk, the Ukrainian Premier League club said on Wednesday.
Should City win on Sunday they would move 10 points clear of Liverpool having also played one game fewer.
Klopp believes that his team is not showing the performance that makes them Premier League title contenders.
De Bruyne, 29, looked to have sustained a leg muscle injury and was replaced on the hour mark at the Etihad Stadium.
The 20-year-old midfielder scored his eighth goal of the season as City beat Premier League strugglers Brighton 1-0.
Manchester City owner Sheikh Mansour bin Zayed Al Nahyan is the new owner of the oldest existing version of the FA Cup trophy.
Five Manchester City first team players have tested positive for COVID-19 and will not be involved when they play Chelsea in the Premier League this weekend.
Lampard says their preparations for Sunday’s Premier League clash against Manchester City will go ahead as planned despite fresh COVID-19 cases at both clubs.
Manchester United and Manchester City will play their rescheduled fixtures from the opening weekend of the season in January.
Manchester City will return to training on Wednesday after a COVID-19 outbreak forced them to close their facilities and postpone Monday’s match at Everton.
Guardiola has challenged his players to work collectively in a bid to rediscover their fluid style of play.
Gabriel Jesus and defender Kyle Walker have tested positive for COVID-19, the Premier League club said on Friday.
Pogba, who joined from Juventus in 2016 for a club record 89 million pounds, has featured in just eight Premier League matches this season.
Guardiola said his players could not revel in their 5-0 victory over Burnley on Saturday as hectic match scheduling had sucked some of the joy out of the sport.
The Spanish manager extended his contract with Manchester City, which led to many speculations about the transfer of Barcelona star to the Citizens.
The Spanish manager will be looking forward to win Manchester City’s first ever Champions League trophy during his remaining time with the Citizens.
Liverpool come third in the table with 16 points from 5 wins, one draw and one loss against Aston Villa.