Roberto Mancini has hit back at Bayern Munich's criticism of Manchester City's spending ahead of Wednesday's must-win Champions League tie at Etihad Stadium.
Bayern CEO Karl-Heinz Rummenigge told Austrian media that City will face difficulties when the financial fair play takes effect from next season.
"I don't understand his behaviour," said City boss Mancini. "We're working hard with the financial rules.
"There are other clubs with financial fair play play problems not just City."
Rummenigge, 56, played for a decade at Bayern from 1974, winning 95 Germany caps.
With Uefa's financial fair play rules being implemented from next season, all clubs taking part in European competitions will have to break even by 2014.
And Mancini added: "I don't know why an important man like him, from a big club, and a great player, keeps talking about us.
"I want to ask him after the game.
"I think everybody is worried about Manchester City becoming one of the great clubs. But why is he always talking about us?"
City need to beat the Germans to stand any chance of reaching the last 16.
Bayern have already qualified for the knockout stages while City were leapfrogged into second by Napoli following their 2-1 defeat in Italy two weeks ago.
City now need to beat Bayern while hoping Spanish side Villarreal, who have lost all five of their group games so far, pick up at least a point at home to Napoli.
Meanwhile Mancini added that it would be best for the team and the player if Carlos Tevez is sold in the January transfer window.