Guardiola said City had asked for the delay because of the club's involvement with the Club World Cup, but said the Premier League would not accept the request.
The final of the 32-team event is set for 13 July at the MetLife Stadium in New Jersey, creating a gap of either four or five weeks to the start of the 2025-26 Premier League season.
Three of those weeks will be mandatory rest periods for the players.
"The Premier League has not allowed us to postpone the first two games for our recovery," said Guardiola. "Thank you so much.
"I think the club asked the league to postpone one or two or three weeks so we can have a holiday after the [Club] World Cup but it is absolutely not allowed. The Premier League say yes to us? No. Absolutely not."
However, after talking to officials at City and the Premier League, the BBC has learned there has been no formal request.