While the Saints enter the competition at this stage, their League Two counterparts have already overcome Sheppey United and Alfreton Town to make it this far.
Match preview
A fifth consecutive Championship triumph was on the cards for Southampton in their New Year's Day encounter with Norwich City at Carrow Road, where Adam Armstrong's 13th goal of the second-tier campaign 20 minutes from time would ostensibly prove decisive.
Joshua Sargent had other ideas, though, drawing the Canaries level just eight minutes after Armstrong's opener to deny Russell Martin's charges a quintet of successive wins, although their remarkable unbeaten streak remains very much alive.
Since being seen off 2-1 by Middlesbrough on September 23 - a result which marked a fourth-straight defeat for the Saints - Martin's men have strung together an exceptional 18-game sequence without suffering defeat, allowing them to cement a third-placed ranking in the Championship table as they bid to return to the Premier League at the first time of asking.
However, the Saints faithful cannot be pre-occupied with thoughts of an immediate promotion back to the big time this weekend, as Southampton - one-time winners of the FA Cup back in 1976 - aim to avoid a third-round exit for the first time since the 2018-19 season.
The hosts have at least reached the fifth round in each of the last three editions, although they were the victims of a Grimsby Town giant killing at that stage last year, and Walsall would do well to take a leaf out of the Mariners' FA Cup book.
Coincidentally, Walsall commenced their 2024 calendar with a New Year's Day clash away to Grimsby, whose adventure to the FA Cup quarter-finals last term made plenty of headlines, and Mat Sadler's side initially went a goal down courtesy of Danny Rose's early strike.
However, Rose's opener for Grimsby sparked a Walsall slaughter, as Saturday's visitors to St Mary's scored six times without reply in a 6-1 obliteration at Blundell Park, leaving Sadler to reflect on an "incredible afternoon" in which his side looked capable of scoring "at will".
The destruction of Grimsby represented a third win on the trot for Walsall in League Two, and six of the visitors' last seven games in all tournaments have ended in victory, including a 1-0 beating of Alfreton in an FA Cup second-round replay after an initial goalless draw.
Consequently, Walsall will be taking part in the third round of the FA Cup for just the second time in the past five seasons - they advanced to round four last year before falling to Leicester City's superiority - but not since 2003 have they gone beyond the third round in successive seasons.
Furthermore, Walsall have never beaten Southampton at St Mary's in a competitive setting, losing their most recent encounter on the South Coast 3-1 in May 2011, where a teenage Alex Oxlade-Chamberlain was among the scorers for the Saints in that League One affair.
Southampton form (all competitions):
D
W
W
W
W
D
Walsall FA Cup form:
W
D
W
Walsall form (all competitions):
W
W
L
W
W
W
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Team News
Southampton held out for a point against Norwich City despite emerging for the second half without Samuel Edozie and Jan Bednarek, the former of whom was taken off on the 27-minute mark with an ankle problem after a crunching challenge from Jack Stacey.
Martin - who lamented the lack of a red card to Stacey for the tackle - admitted at the time that he did not know how severe Edozie's concern was, while Bednarek was hauled off during the interval and may need a once-over ahead of the third-round tie too.
Juan Larios (unspecified), Kamaldeen Sulemana (hamstring), James Bree (hamstring) and Ross Stewart (muscle) are also out of contention, and Joe Aribo has been called up to represent Nigeria at the Africa Cup of Nations.
Walsall also came out of their most recent league outing with a fresh attacking concern, as 19-year-old striker Freddie Draper - on loan from Lincoln City - lasted just 33 minutes before succumbing to an unspecified concern.
It is still not clear how serious Draper's affliction is, but Walsall are already guaranteed to be without the services of several players, including Ryan Stirk (ankle), Ross Tierney (hamstring), Joe Riley (knee) and Aramide Oteh (hamstring).
Oisin McEntee is also at risk of missing the rest of the season with a hamstring injury, while Harry Williams (abdominal) and Jamille Matt (groin) will both need assessing closer to the time.
Southampton possible starting lineup:
Lumley; Walker-Peters, Stephens, Harwood-Bellis, Manning; Alcaraz, Smallbone; Fraser, S. Armstrong, Mara; Adams
Walsall possible starting lineup:
Smith; Okagbue, Daniels, Farquharson; Knowles, Earing, Hutchinson, Comley, Gordon; James-Taylor, Johnson
We say: Southampton 3-1 Walsall
Both sides have bigger promotion fish to fry in the coming months, but if the visitors' recent offensive exploits are anything to go by, Walsall ought to give an injury-hit Southampton a scare or two.