Rooney's tenure saw the team secure only two victories in 15 games, with nine losses and four draws. This disappointing run caused Birmingham to slide from a playoff position to the 20th spot in the league table in less than three months, a stark contrast to their sixth-place standing when Rooney assumed the managerial role.
Interestingly, between Rooney's first and last game in charge, Birmingham accrued fewer points, suffered more losses, and conceded more goals than any other team in the Championship. The final straw came in the form of a 3-0 defeat at Leeds United on New Year's Day, marking the end of Rooney's stint at the helm. As he departs, Birmingham finds themselves six points clear of the relegation zone.
"We are committed to doing what is necessary to bring success to St Andrew's," read a statement from CEO Garry Cook.
"Unfortunately, Wayne's time with us did not go as planned and we have decided to move in a different direction.
"The search for a successor begins with immediate effect and we will update supporters when we have further news."
Rooney also released a statement in the wake of the decision, saying:
Rooney now holds the title of Birmingham's second-shortest-serving permanent manager, measured by the number of matches played, coming in just after Harry Redknapp's 13-game tenure in 2017. Additionally, Rooney's win percentage stands at 13.3%, making it the second-lowest in the club's history, surpassed only by Gianfranco Zola's 8.3%."I would like to thank Tom Wagner, Tom Brady and Garry Cook for the opportunity to manage Birmingham City FC and the support they all gave me during my short period with the club.
"Football is a results business - and I recognise they have not been at the level I wanted them to be.
"However, time is the most precious commodity a manager requires and I do not believe 13 weeks was sufficient to oversee changes that were needed.
"Personally, it will take me some time to get over this setback. I have been involved in professional football, as either a player or manager, since I was 16.
"Now, I plan to take some time with my family as I prepare for the next opportunity in my journey as a manager.
"Finally, I wish Birmingham City FC and its owners my best wishes in the pursuit of their ambitions."
In the wake of these changes, first-team coach Carl Robinson has also been relieved of his duties. Professional development coach Steve Spooner will step in as the interim leader of the senior side until a permanent successor is identified.