Current Bayern Munich coach Louis van Gaal has been severely criticised by the veteran Brazilian striker Giovanni who played under the Dutchman during a spell with Barcelona more than a decade ago.
The 38-year-old, who is currently on Santos' books, was sidelined by van Gaal during his time at the Camp Nou, prompting him to move to Greek side Olympiacos.
Giovanni told Marca: "Van Gaal is the Hitler of the Brazilian players. He is arrogant, proud and has a problem.
"My life with him was horrible. The Brazilians did not want him. He put me down and also fought with Rivaldo and Sonny Anderson. He always gave us the excuse that we were not training well.
"I know that he must have some trauma. He has no idea of football and does not know anything. In the time I was with him he always did the same training. His type is sick, he's crazy."