Wayne Rooney claims Birmingham minority owner Tom Brady's criticism of him during his spell as the club's manager was "very unfair".
Rooney, sacked by Birmingham in January 2024 after less than three months in charge, said he was "really disappointed with the comment" on his new podcast, The Wayne Rooney Show.
NFL great Brady, who became a minority shareholder at Birmingham in August 2023, said he was "a little worried about our head coach's work ethic" during a documentary after visiting Blues' training ground the following November.
Former England captain Rooney said he was "really disappointed" at the seven-time Super Bowl winner's criticism.
Speaking via his new show on the BBC, the ex-Everton and Manchester United striker said: "I think Tom came in once, which was the day before a game where the days are a little bit lighter anyway, and I don't think he really understood football that well.
"But what he does understand is - he's a hard worker - we know that."
Rooney added: "Football is not NFL - NFL works for three months a year. Players do need rest as well, so I think he's very unfair, the way he's come out and portrayed that."
Birmingham were bought out by American consortium Knighthead Capital Management in the summer of 2023 and Brady became a shareholder two months later.
Rooney was sacked following 15 matches after Blues had slipped to 20th in the Championship and the club were relegated at the end of the 2023-24 season.
Under current boss Chris Davies, Birmingham bounced straight back to the second tier as League One champions last season with an English Football League record points tally of 111.
BBC Sport's The Wayne Rooney Show is out tomorrow on BBC Sport's YouTube channel and BBC Sounds
