A late equaliser on Wednesday earned John Eustace's men a respectable point against Swansea City, whereas Sunderland were last in action nearly a week ago when they narrowly lost to Cardiff City at the Stadium of Light.
Match preview
After a period of tough fixtures and a few key absences, Wednesday's assignment against Russell Martin's Swansea looked at one stage to be a step too far for Birmingham in their ascent up the Championship table.
Scott Hogan headed in his ninth goal of the campaign from a pinpoint cross to open the scoring for the hosts, but a severe wave of Swans pressure followed which Blues were unable to weather, coming in at half time 2-1 down.
The Birmingham midfield dearly missed the anchoring presence of the suspended Krystian Bielik to break up attacks, as well as veteran central defender Harlee Dean, who picked up a knock in Blues' win at Stoke City last weekend.
To the surprise of both sets of supporters, the second half saw complete domination from Eustace's side, who pushed back a Swansea team renowned for their possession football, and in the 89th minute that pressure paid off when Blues captain Troy Deeney finished from close range to force a share of the spoils.
Now six unbeaten at home, Birmingham will be confident in ending this part of a unique Championship season on a high against Sunderland, with a win good enough to take them into the top six on Friday night, even if it is for only 24 hours.
Two Swansea goals last time out mean Blues no longer have the best defensive record in the second tier, but conceding just 18 goals in their opening 20 matches is a real achievement for a side that allowed 75 strikes past them last campaign.
Last season's League One playoff winners Sunderland have been brought back down to the reality of life in the Championship after a blistering start, one which had some of the most optimistic supporters wondering about the possibility of consecutive promotions.
Since the middle of September, Tony Mowbray's men have won just two of their 10 second-tier matches, a poor run of form which has seen them drop down to 17th in the league standings with the World Cup break awaiting the Black Cats when the full-time whistle sounds in Birmingham.
Injuries to key players during that spell have not helped Sunderland keep up their early-season momentum, with Mowbray perhaps viewing the month-long hiatus as a good opportunity to nurse several of his men back to full health for when their season resumes at home to Millwall in December.
With the fifth-best away record in the division, Mowbray's side have the ability to record maximums on their travels and score plenty of goals as they do so, with their 14 strikes on the road only bested by league-leaders Burnley and Middlesbrough so far this season.
The visitors will be backed by a sold-out away section at St Andrew's on Friday night as they look to earn back-to-back away wins before the unprecedented mid-season break in which they will be able to look back at a satisfactory start to life back in the Championship.
Birmingham City Championship form:
D
L
W
D
W
D
Sunderland Championship form:
W
L
L
D
W
L
Team News
Birmingham will welcome Polish international Bielik back into the starting XI after he served a one-match suspension last time out for collecting five yellow cards.
Eustace informed the media after the draw with Swansea that 31-year-old Dean had picked up a calf knock in the late stages at Stoke last weekend, with the defender a doubt for Friday's matchup against the Black Cats.
Dean has been blighted with calf issues over the course of 2022 and Birmingham will be praying the injury is not as serious as the one that kept him out for 10 weeks at the start of this campaign.
Sunderland will be without the services of Luke O'Nien at St Andrew's after he picked up his fifth booking of the season against Cardiff last weekend, with youngster Trai Hume the most natural replacement at right-back.
Ross Stewart, Dan Ballard and Aji Alese are all recovering from their respective injuries and are targeting returns when the Championship resumes in early December.
Birmingham City possible starting lineup:
Ruddy; Colin, Sanderson, Trusty; Bacuna, Bielik, Hannibal, Chong, Longelo; Deeney, Hogan
Sunderland possible starting lineup:
Patterson; Hume, Wright, Batth, Cirkin; Neil, Evans, Roberts, Diallo, Clarke; Simms
We say: Birmingham City 2-1 Sunderland
Birmingham are defying pre-season predictions of relegation and showing the Championship they are a hard matchup for any side in the division after a spell which leaves them in touching distance of the top six.