Having both come out on top in their respective last outings, the teams will head into this one with the wind in their sails as they look to progress at the expense of each other.
Match preview
Birmingham got their EFL Cup journey up and running with a 2-0 triumph over Cheltenham Town when the sides faced off at Whaddon Road on August 8.
A quickfire double from Juninho Bacuna eight minutes apart in the first half was enough to get the job done for John Eustace's men in a one-sided affair.
Since then, the Blues have picked up three straight league wins which have propelled them to third place in the Championship table, two shy of leaders Leicester City.
Up next is the challenge of an opposing outfit who are without defeat in the last nine editions of this fixture across all competitions dating back to 2018.
Currently on a run of three straight victories in front of their fans, Tuesday's hosts will seriously fancy their chances of making home advantage count once again and making it through to the next phase of the EFL Cup.
Cardiff City needed the luxury of penalties to see off the threat of League Two side Colchester United on August 9 in the first round of the EFL Cup.
After racing to a two-goal lead through strikes from Rubin Colwill and Kion Etete, Erol Bulut's men were pegged back by goals from John Akinde and Joe Taylor which took the tie to a shootout where Ike Ugbo held his nerve to score the decisive spot-kick.
The Bluebirds lost their subsequent two league outings but have since returned to winning ways by defeating Sheffield Wednesday on Saturday, moving up to 17th in the Championship standings as a result.
Winless in their last six matches on the road, Tuesday's visitors will need to get going away from home to stand any chance of emerging victorious here.
Birmingham City EFL Cup form:
W
Birmingham City form (all competitions):
L
D
W
W
W
W
Cardiff City EFL Cup form:
W
Cardiff City form (all competitions):
D
D
W
L
L
W
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Team News
Marcel Oakley is still sidelined for Birmingham with a muscle injury which he sustained in his last EFL Cup outing against Cheltenham Town.
Tyler Roberts is also unavailable for the home side due to a calf problem but George Hall is back in contention having made his return from a calf problem last time out.
Cardiff's Ryan Allsop has missed five straight games due to a knock and the Englishman remains a major doubt for Tuesday's trip to Birmingham.
Twenty-four-year-old Ike Ugbo has found the back of the net in three of his five matches this term, making the forward one to keep an eye on.
Birmingham City possible starting lineup:
Ruddy; Bacuna, Sanderson, Long, Buchanan; Bielik, Sunjic; James, Miyoshi, Anderson; Hogan
Cardiff City possible starting lineup:
Alnwick; Ng, McGuiness, Goutas, Collins; Siopis, Ralls; Ugbo, Ramsey, O'Dowda; Meite