I think Manchester City didn't play as well as they normally would. But it's also definitely due to the missing players, Rodri, Silva and Bruyne are actually top players who almost always play from the start and can also make a difference in the match. Then City has to play in CL as well, so it's not easy for Pep.
A surprise today after City won all 6 games. Now the mistake, but it almost does not matter, they are still on 1st place in the league, 1 point ahead. Next week there is a topmatch Arsenal against Manchester City and Arsenal has not lost for 11 games. The last game fron both was decided on penalties, 4:1 for Arsenal in the Community Shield. Before that Arsenal could not win against City in the Premier League since 2015.