The Beady Eye musician expressed his sadness at the dismissal in light of his past triumphs, including a first ever Premier League title, but conceded he was not surprised
The former Oasis and current Beady Eye star had been a strong advocate of City keeping the Italian despite watching the club relinquish the Premier League title to rivals Manchester United before being beaten by Wigan in the FA Cup final.
Mancini was sacked 48 hours after their Wembley loss, a year to the day after securing a first title in 44 years, with Manuel Pellegrini revealing he is due to hold talks with the Etihad Stadium outfit about succeeding the Italian - and Gallagher expressed his sadness at the former Inter manager's dismissal.
"I am [sad to see him go]," Gallagher told Absolute Radio. "He won us the league for the first time in 40 years, got us the FA cup, got us in Europe loads of times, that’s just how it is these days, isn’t it?
"This time last year, we were champions and now the guy’s been sacked.
"It’s just insane, man, the world’s gone mad. But that’s what happens if you don’t keep on top of your s***."
Listen to Beady Eye's interview in full on Absolute Radio on Thursday from 9pm.