Blues were deservedly beaten at Ipswich Town last weekend, whereas the Saints exited the FA Cup at the hands of Premier League Liverpool on Wednesday night.
Match preview
Birmingham were unable to record three-straight victories in the Championship for only the second time this season after losing 3-1 to Kieran McKenna's top-two chasing Ipswich side at Portman Road last weekend, with the visitors beginning a spell without Tony Mowbray on a bad note.
Blues' interim head coach Mark Venus would have been delighted to get his men into the dressing room level at the half-time whistle after Jordan James's eighth league goal of the campaign cancelled out Conor Chaplin's opener, however the Tractor Boys rallied in the second period, with Jeremy Sarmiento and Omari Hutchinson strikes sealing maximum points.
On a weekend when six of the bottom eight in the Championship ended up victorious in their respective fixtures, a defeat for Birmingham in East Anglia threw them straight back into the relegation fight following back-to-back home wins, with the Second City club now just three points above 22nd-placed Stoke City.
Level with Wales international James at the front of Blues' Golden Boot race, Fulham loanee Jay Stansfield has made the central-striking role his own in recent weeks after the departure of Wayne Rooney, with the 21-year-old attracting interest from Ipswich and Southampton during the January window.
Birmingham will be hoping for a repeat of their last game at St Andrew's @ Knighthead Park on February 17, when second-half strikes from James and Koji Miyoshi bested Sunderland and sent a sold-out crowd in the Second City into delirium, signalling the end of Michael Beale's short tenure as Black Cats boss.
Following a record-breaking 25-game unbeaten run between late September and the middle of February, Southampton have now lost four of their last five matches across all competitions after being knocked out of the FA Cup at the fifth-round stage by Premier League side Liverpool at Anfield.
A much-changed Saints side showed signs of being able to spring a cup upset against Jurgen Klopp's youthful XI in Merseyside, however the hosts took the game away from Russell Martin's men after the 40-minute mark, with a Lewis Koumas strike and a Jayden Danns brace securing a three-goal success.
Attention will now return to Championship matters for Southampton, who lost significant ground in the top-two race following back-to-back home defeats to Hull City and Millwall at the end of February, meaning that the South Coast club are now five points behind second-placed Leeds United.
With an Elland Road showdown scheduled versus Daniel Farke's charges on the final day of the second-tier season, the Saints will be hoping to stay in the pursuit of automatic promotion by the time they make the potentially campaign-defining trip to Yorkshire on May 4.
Earning a rest from the start at Anfield on Wednesday night, Adam Armstrong is fully expected to regain his spot in the Southampton XI during the trip to Birmingham - only Sammie Szmodics (18) and Morgan Whittaker (17) have netted more than the 27-year-old's 16 goals in the Championship so far.
Birmingham City Championship form:
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Birmingham City form (all competitions):
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Southampton Championship form:
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Southampton form (all competitions):
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Team News
Birmingham's Krystian Bielik is a doubt for Saturday's clash due to a groin injury, meaning that Dion Sanderson and Marc Roberts could be centre-back pairing once again.
Perhaps looking for greater defensive stability than at Portman Road last time out, Blues could bring Lee Buchanan in at left-back, with Cody Drameh potentially dropping out of the side.
Alex Pritchard has trained this week as he steps up his recovery from a calf strain, although it remains to be see whether the former Sunderland man makes the squad this weekend.
After making eight changes for the FA Cup loss at Liverpool, Southampton are expected to reintroduce a raft of their first-team stars into the side, including William Smallbone, Taylor Harwood-Bellis and leading marksman Armstrong.
Kyle Walker-Peters is a major doubt after he was forced off during the defeat at Anfield, meaning that his ever-present status in the Championship this season is under considerable threat.
With the former Tottenham Hotspur man potentially sidelined, James Bree could earn a rare league start on the right side of the Saints' defence.
Birmingham City possible starting lineup:
Ruddy; Laird, Sanderson, Roberts, Buchanan, Paik, Dozzell, Miyoshi, James, Bacuna; Stansfield
Southampton possible starting lineup:
Bazunu; Stephens, Harwood-Bellis, Bednarek, Manning; Smallbone, S Armstrong, Aribo; Sulemana, A Armstrong, Adams
We say: Birmingham City 1-2 Southampton
Birmingham are weaker without manager Mowbray in the dugout, but Blues always make a good fight of it against the division's biggest teams at St Andrew's.