The top two teams in the league are due to meet at the Emirates on Oct. 19, but Guardiola suggested the game could be postponed to accommodate Arsenal's Europa League game against PSV Eindhoven.
PSV's trip to London, scheduled for Thursday, has been moved ahead of Queen Elizabeth II's funeral on Monday.
The game will have to be played before the first Europa League knockout draw on Nov. 7 and the week of City's game against Arsenal is one option for the rearranged date.
"Always the fixtures were so tight every season," Guardiola told a news conference on Tuesday.
"After the international break, we'll have one month and a half with a lot of games. We have seven Premier League games, five games at home, it depends if the Arsenal game will be postponed or not. Then the World Cup."
Guardiola, though, said he was concerned at being asked to play Borussia Dortmund in the Champions League at 8pm on Wednesday and then against Wolves at Molineux at 12.30pm on Saturday.
"We have to arrive at the World Cup being close to the top and then we see how we come back. In the Champions League, we are going to face a team who won the first game, we have to be strong at home and if we are we will be there.
"Playing Wednesday and Saturday 12.30pm is the risky one -- a team like Wolves who have a long two weeks to prepare for the game.
"It's why I have 20 players and I'm pretty sure they will all play in each game, that's my feeling right now."
Borussia Dortmund arrive at the Etihad Stadium ready to face their former striker Erling Haaland, who has scored 12 goals already this season.
Ilkay Gundogan is another former Dortmund player in Guardiola's squad and, ahead of the game, the German midfielder said he was in no rush to decide his next move despite entering the last year of his contract at City.
"I'm very happy [here, like] I was throughout all my time at the club, but obviously it's football and in some ways it's also a business," Gundogan added.
"We will see what will happen at the end of the season but I just try to contribute to the team in the best way possible and then we will see what happens next season."