City finished the campaign trophyless, though did scrape into the Champions League qualifying places.
"I said many times, the season was not good," said Guardiola. "When you finish third in the Premier League to qualify for the Champions League, it means 70 teams were worse than us.
"We played the FA Cup final in an incredibly high level against a really good team. The disappointment was the Champions League, we did not do really good. It was tough to handle it.
"Winning this competition is not going to change that but my mindset at the moment is not about winning the competition. We can extend our time here, being here longer.
"For the South American teams, the competition may be the maximum. For European teams, it is a World Cup."
City meet Al Ain on Sunday in their second group tie.