The Irishman, who turned professional with City in 2003, last week signed a new two-year deal at St Andrew's which will keep him at the club until 2015.
After being behind Maik Taylor in the pecking order, Doyle established himself as number one towards the end of the promotion-winning 2006/07 season and started the following Premier League campaign between the posts.
But Taylor quickly regained control before Joe Hart was brought in on loan from Manchester City in 2009/10, with Ben Foster, Boaz Myhill and then Jack Butland subsequently taking the gloves in successive seasons.
Yet Butland's departure to Stoke means Doyle is set to fight it out with new signing Darren Randolph next term. The 27-year-old told the club's official website: "I hope this year I get a few more appearances.
"On a personal level, last year was frustrating because I only played three games, which were the cup games.
"I signed last summer thinking I had a chance of being number one because we knew there was an offer in for Jack (from Southampton) and I didn't know whether the club were going to accept it or not.
"I stayed and it was disappointing to get so few appearances, but Jack obviously did very well in the games he played last season. It just shows by where he is now that he'll move on to better things."
Doyle added: "It's not like I've been behind bad keepers, I had Maik (Taylor), then Joe (Hart) came in, then Fozzy (Ben Foster), Boaz (Myhill) and then Jack (Butland). They're all established international keepers."
Meanwhile, 18-year-old goalkeeper Nick Townsend has signed his first professional contract at Birmingham along with fellow youngsters Charlee Adams and Liam Truslove.