The Black Cats have only managed back-to-back victories once so far this season, when they followed up their Premier League success against Blackburn with victory at Norwich in the Carling Cup.
Bruce watched his side suffer a 3-1 reverse at newly-promoted Burnley on Saturday as they failed to build on an impressive 4-1 home victory against Hull City in their previous clash.
Birmingham make the trip to the North East crippled by injuries and struggling for goals, but lifted by their 1-0 triumph against Hull at the KC Stadium on Saturday.
Alex McLeish could not even find enough players to fill his bench at the weekend, while the Blues' winning goal from Garry O'Connor was only the fifth they have managed in seven games this term.
They found the net twice in the second round success away to Southampton but have otherwise struggled to break opponents down, although Christian Benitez looked lively on his full debut against the Tigers.
Team newsBruce will hand summer signings John Mensah and Paulo da Silva their first home starts in the third round clash.
Ghana international Mensah made his debut as a substitute in the victory over Hull on 12th September, while Paraguay skipper da Silva started the 4-1 win at Norwich in the second round.
However, midfielder Lee Cattermole, who missed Saturday's defeat at Burnley with a heel problem, remains a doubt, while keeper Marton Fulop is still out with a similar problem.
Blues boss McLeish does not have the option of resting players with his squad ravaged by problems.
Wide man Sebastian Larsson (hamstring) is a recent addition to the injury list, while full-back Stephen Carr has suffered a recurrence of his thigh problem.
James McFadden (thigh), Cameron Jerome (ankle), Franck Queudrue, Gregory Vignal, Marcus Bent (all hamstring), Martin Taylor (ankle), Lee Carsley (back), Damien Johnson (strain) and David Murphy (knee) all remain unavailable.
Liam Ridgewell is expected to return at left-back having made a quick recovery from a broken leg, while there may be a debut for Giovanny Espinoza.