Nigel Pearson is counting down the days until he can make changes to his squad in the transfer market after lamenting his side's defending in a third consecutive defeat.
The Robins were slow out the starting blocks, conceding after just two minutes through Taith Chong before Nico Gordon headed in from a corner in the 13th minute to double Birmingham's lead.
The home faithful made their thoughts on the first half performance known after the opening 45 minutes but two changes at the break and a switch to a back three had an immediate impact as Alex Scott restored some hope.
