City have completed a deal with the Bundesliga champions that could be worth a potential £55million.
Sane, 24, had already agreed a five-year contract with the German champions after making it clear his future lay away from the Etihad Stadium - and Guardiola spoke about the deal on Wednesday.
"Looks like, if not already, done," Guardiola said, speaking at his pre-match press conference ahead of the clash against Liverpool on Thursday. "There are still some little issues. Wish him all the best on his new chapter.
"He will have another chapter at a fantastic club in Bayern Munich. He wanted to leave. Everyone has their own life and he decided to move on.
"I would have loved for him to stay but he believed he would be better and happier there."