The Spain international announced on Friday afternoon that he will leave Camp Nou at the end of the season following a glittering 22-year spell with the club.
Fellow La Masia graduate product Guardiola played alongside Iniesta and then managed him for four seasons, and he claims that Barca's success would not have been possible without the 33-year-old in their ranks.
"I could spend so many minutes talking about what Andres Iniesta means to Barcelona and football," he told reporters. "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. 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."
Iniesta is expected to continue his playing career in the Chinese Super League later this year.