Since Guardiola took charge of Bayern in June, the European champions have dropped only two points, winning six Bundesliga games ahead of their Champions League date with Manchester City on Wednesday.
Guardiola and Ibrahimovic were united at Barcelona for the 2009/10 season, but their relationship soon soured when the Sweden international lost his place in the starting line-up.
Ibrahimovic's recent autobiography recalls some of the disagreements between the pair and in an interview with Spiegel, the frontman reacted bluntly when questioned about Guardiola, who he dubbed "the Philosopher" during his spell at the Nou Camp.
"Guardiola is a fantastic trainer, but as a person? He is a coward," the 31-year-old said in the interview.
"He isn't a man. In the first months at Barcelona things went well and I scored lots of goals.
"Then he sacrificed me for Lionel Messi, but didn't have the guts to tell me."
Guardiola was not alone in receiving criticism from Ibrahimovic as Louis van Gaal was also slated in the book 'I am Zlatan Ibramhimovic', while Chelsea manager Jose Mourinho received high praise after the pair worked together at Inter Milan.
However, Bayern president Hoeness has hit back at Ibrahimovic's comments, claiming he needs to accept the decisions which have been made by his previous managers.
"For me (Zlatan) Ibrahimovic is just an aggrieved prima donna. He has not yet accepted his leaving from Barcelona," he told Bild.
"No club that signed him has even been happy with his signature. It is a fact that he is the main problem!"