At a time when the Saints are fourth in the standings, Watford's own improvement has taken them into 10th position.
Match preview
Although Valerien Ismael would have been encouraged by the backing that he has received from the Watford hierarchy, he has still been required to justify his surprise new contract.
As it stands, he and his Hornets squad have delivered, a run of five wins and three draws having been recorded from their last nine fixtures.
Watford still only sit in 10th, highlighting their relatively poor start, but momentum is building with their only recent setback coming away at leaders Leicester City.
Their performances in Hertfordshire have been key, Watford collecting 10 points from a possible 12 with their most recent home win over Norwich City coming after they had been two goals down during the early stages.
That was backed up by an impressive 2-1 success at sixth-placed Hull City last time out, and the belief is there that they can end Southampton's lengthy unbeaten run.
Russell Martin's team have now gone 11 games without suffering a defeat, posting eight wins and three draws during that period.
Unlike in the early weeks of Martin's reign, solutions have been found in defence, the Saints going six games without conceding more than one goal in a single fixture.
Four triumphs on the spin have been recorded at St Mary's, most recently against Cardiff City as they netted twice in the opening 15 minutes to run out 2-0 victors.
Southampton have also gone five games unbeaten way from home, but they did drop points in their most recent such contest at Huddersfield Town through conceding a late equaliser in a 1-1 draw.
Watford Championship form:
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D
W
L
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W
Southampton Championship form:
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D
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Team News
On the back of such an impressive win at Hull, Ismael is likely to keep changes to his Watford side to a minimum.
However, Tom Ince and Vakoun Bayo are both in contention to return in the final third, with Yaser Asprilla potentially dropping out.
Despite his recent return from suspension, goalkeeper Daniel Bachmann is expected to remain on the substitutes' bench with Ben Hamer impressing in his absence.
With Southampton comfortably disposing of Cardiff last time out, Martin may be prepared to name the same starting lineup.
Although Joe Aribo impressed as a substitute in that fixture, the playmaker will likely have to make do with a spot among the replacements.
The likes of Will Smallbone and Ross Stewart are expected to remain absent through injury.
Watford possible starting lineup:
Hamer; Andrews, Porteous, Hoedt, Lewis; Kayembe, Livermore, Kone; Ince, Rajovic, Sema
Southampton possible starting lineup:
Bazunu; Walker-Peters, Harwood-Bellis, Bednarek, Manning; Charles, Downes, S.Armstrong; A.Armstrong, Adams; Alcaraz
We say: Watford 1-2 Southampton
With both teams very much in form, this is a tough match to predict. Watford are growing in confidence, particularly at home, but Southampton have scored a lot of late decisive goals this season and we feel that a similar outcome may materialise here.