The veteran midfielder announced on Friday he will be leaving Camp Nou at the end of the season following 22 successful years in Catalonia, in which he has lifted 31 trophies with the club.
Iniesta, who also won the European Championship twice and scored Spain's winning goal in the 2010 World Cup final, is one of the most decorated graduates from Barcelona's famed La Masia academy and played alongside Guardiola, before working under him when the now Manchester City boss was in charge of the Blaugrana.
Speaking at City's news conference ahead of Sunday's clash with West Ham, Guardiola heaped praise on the Spain international, whose next club is likely to be in China.
"I could spend so many minutes talking about what Andres Iniesta means to Barcelona and football," Guardiola said.
"The history Barcelona have lived in the last 15 years would not be possible without him.
"I need to thank him because he helped me to understand the game better - just watching him, what he does on the football pitch.
"As well as the amount of titles he won, it was the way he played that is an example of how you have to be as a professional on and off the pitch.
"Thank you so much for what he has done and all the best in the future."
He added: "Hopefully when he retires he can come back to Barcelona and can teach the young players what he has shown on the pitch.
"It was an incredible period for me, first as his team-mate and then as his manager. I learned a lot from him."