Pep Guardiola says he is baffled by some of the coronavirus rules in the game, admitting he does not understand why certain matches have been postponed while others have gone ahead.
Four Premier League matches have so far been called off, including City's trip to Everton last month, but a different approach appears to have been taken in the FA Cup over the weekend.
Both Aston Villa and Derby fielded sides made up of youth players for their third-round ties after their entire first-team squads were told to isolate.
The Premier League last week called on players to tone down their celebrations in a set of reinforced Covid-19 protocols that also emphasised the need to avoid handshakes and shirt-swapping.
City's own problems with the virus have continued, with Sergio Aguero forced to miss Sunday's 3-0 victory over Birmingham in the FA Cup third round.
The Argentine has been told to self-isolate after it was discovered he is a close contact of someone who has tested positive for the virus.
City have already been without eight other players following positive tests at various stages since Christmas Day.
Guardiola said the club would follow the new protocols but he said it was unrealistic to expect players not to celebrate goals.
"All of us (involved on match days) are tested negative, every two days. I don't know what is going to happen -- but one guy scores a goal, the joy to celebrate it, I don't know if he is going to think 'I cannot hug my mate for two, three seconds'," he said.
"There are teams with four or five cases and played 10 players from the under-23s in the FA Cup. We are four or five, the same situation, and we are here.
"One guy is isolated and the group has to continue. So, I don't know. We follow what the people say at the club, the Premier League. We follow the rules. That is what it is."