Sky Sports understands Birmingham are set to sign experienced goalkeeper David Lucas.
The 34-year-old has been released from his player-coaching role at Rochdale following the club's relegation from League One last season.
Birmingham sold Ben Foster on a permanent basis to West Brom last month, while Boaz Myhill returned to the Baggies following his loan spell.
Blues also face the prospect of losing youngster Jack Butland ahead of the coming season.
As a result, they are keen to add experienced and affordable cover and new manager Lee Clark believes Lucas fits the bill.
Lucas played 20 games for Rochdale last season in a career that has also included spells at Preston, Leeds and Sheffield Wednesday.