Die Roten's advisor predicts the club will be unstoppable once its new coach has imposed his methods on the team, anticipating further improvement for the dominant Bavarians.
The Bavarian outfit has already secured this season's Bundesliga, maintaining its 20-point lead with a 4-0 win over Nurnberg on Saturday, and plays Wolsfburg in a DFB-Pokal semifinal on Tuesday before meeting Barcelona in the Champions League semifinals a week later.
Despite Jupp Heynckes leading his side to the verge of a potential treble, Breitner believes much better is to come once Guardiola arrives.
"We want to be the dominant club in Europe," Breitner told ESPN Brasil. "This role it has played in recent years by Barcelona. I'm convinced that, under Guardiola, in 12 to 18 months' time we will assume this leadership position.
"The 13 million Bayern fans in Germany are euphoric. Since announcing his [Guardiola's] arrival, top players have said 'I want to play for Bayern', and this is going to continue over the next few months."
Breitner, a European Cup winner with Bayern in 1974, threw his unwavering support behind the former Barcelona boss, stating his belief the Spaniard will inspire the club to reach new heights.
"Guardiola will represent a very positive impact for Bayern and the Bundesliga," Breitner said. "We are ambitious, we want the best and we have started with the best coach in the world.
"Guardiola is able to improve the players when working with them every day. Step by step we will get to being the best."