Gallagher believes Manuel Pellegrini will eventually fill the void at the Etihad.
He told Absolute Radio: "I thought it was a bit harsh, I thought this would've given him another year, but when you own the club and that and you've got to go, you've got to go and that's it. He obviously didn't get on with a lot of people, but I was a bit shocked got to say.
"Pellegrini seems to have got the job, so I don't know." Gallagher was speaking to Absolute Radio Rock n' Roll Football. For more, visit absoluteradio.co.uk/football.