Luca Toni revealed he almost came to blows with Manchester United manager Louis van Gaal when he played under the Dutchman at Bayern Munich.
Hellas Verona striker Toni, 38, is calling time on his playing days at the end of the 2015-16 season after a 22-year professional career.
The 2006 World Cup winner made the decision after a "terrible" season with Verona, with the club already relegated to the Serie B.
Toni's relationship under Verona coach Luigi Delneri was a complicated one, but the forward admitted he had played under worse in his storied career.
"[Delneri and I] didn't get along very well, that's for sure," Toni told Italian TV after helping Verona to a 2-1 win over Italian champions Juventus on Sunday.
"But it is not nice talking about it now. In any case we cleared the air.
"In the past I had much worse misunderstandings with Van Gaal when I was playing at Bayern Munich.
"Back then we almost came to blows."
As for what the future holds for Toni, the two-time Bundesliga winner said he does not envisage going down the coaching path.
"I have seen my former team-mates age five years every 12 months since they became coaches," he said. "I'd prefer to do something in a directorial role.
"I will speak to Verona and the president, because I still owe the city something. I'd like to help this club get back into Serie A, because it is where they deserve to be.
"If not then I'll look around for something to do, because I doubt my wife wants me hanging around the house too much."