Yet Guardiola expects the club to be in the Champions League next season.
City lost their Premier League crown to Liverpool last month but can still add the FA Cup and the Champions League to their League Cup win in March.
"I am honest with them and the moment I am going to feel - not with John but any player - if we have to change we are going to let them know".
"But if it happens like it did against Southampton, Tottenham at home and away and Norwich away, we will be out [of the FA Cup] and Arsenal will be in the final and Madrid will go through [from their Champions League round-of-16 tie]".
Due to the COVID-19 outbreak, UEFA initially wanted those remaining games played in Lisbon, Portugal, where the tournament will be completed on a single-game knockout basis after the last 16.
Guardiola, who was speaking at an online press conference to preview Wednesday's game against Newcastle, accepts this problem has bedevilled him all season.
Bucks’ facilities to stay closed until team goes to Orlando
Once the league has assembled there, all will isolate until they test negative for coronavirus on consecutive days. The first scrimmage game for the Bucks in Orlando is scheduled on July 23rd against the San Antonio Spurs.
"I told you many times no".
'The commitment of the players is without a doubt still, after two or three successful seasons, unbelievable but we are in the point where we sometimes make mistakes, ' Guardiola said. I've got Brighton [in the Premier League on Saturday] and continue to prepare for Arsenal [in the semi-finals of the FA Cup].
Since the English top-flight's return from a three-month coronavirus pandemic-enforced hiatus in June, matches have stopped midway through each half to allow players to rehydrate.
"The Court of Arbitration for Sport (CAS) will announce the decision taken in the arbitration procedure between Manchester City Football Club and the Union of European Football Associations (UEFA) on Monday, 13 July 2020", CAS said in a statement.
City boss Guardiola has blamed too many errors for his team's failure to defend their Premier League title this season.