Messi, who is presently in Manchester for the Champions League quarter-final clash against Manchester United, is known to be the star behind Barca’s successes in the Champions League under Guardiola.
Eto’o and Messi played together in two finals; a 2-0 win against United in Rome 10 years ago and the 2011 win against the same side at Wembley.
The Cameroonian scored 130 goals in nearly 200 appearances.
Speaking to beIN SPORTS, he said: “I’ve said to Guardiola you will apologise to me because it’ll be me that will make Barcelona win, not Lionel Messi.”
“It was a situation back then.
“Messi would come later but you can ask Xavi, Andres Iniesta and all the others.
“That was my era.
“It was me that made Barca win and Guardiola would ask me for forgiveness.”
The striker criticised the Manchester City manager’s approach during his time with Barcelona.
”Pep has lived his whole life in Barcelona, but in the years I spent in Barcelona, he didn’t understand the squad. He didn’t live the life of our group,” he said.