The Hornets are aiming to return to the pinnacle of English football at the first time of asking, while the Blades are preparing for a second consecutive year in the second tier.
Match preview
Forest Green Rovers did not make any effort to hide their displeasure at Rob Edwards's departure for Watford, and the 39-year-old is now aiming to avoid becoming the next victim of the Hornets' trigger-happy board.
Xisco Munoz, Claudio Ranieri and wily veteran Roy Hodgson all tried and failed to keep Watford afloat in the Premier League last season, and competing at the top end of the Championship table this time around is a prerequisite for Edwards.
However, only one of Watford's five pre-season fixtures ended in victory - a 4-1 thrashing of Wycombe Wanderers - as they drew with Panathinaikos and Southampton while losing to Cambridge United and Bolton Wanderers.
Still searching for their first home league win of 2022, Watford can take solace in the fact that only one of their last 15 opening-day matches has ended in defeat, which is more than can be said for the Blades.
Seeking to avoid even more playoff heartache in 2022-23, Sheffield United came so close yet so far to an immediate return to the top tier last term, finishing fifth in the regular season and booking their spot in the playoffs in the process.
Rewarded for their efforts with a tie against Nottingham Forest, Paul Heckingbottom's side drew 3-3 with the Tricky Trees after extra time in their two-legged tie, but Morgan Gibbs-White - who netted in the 2-1 second-leg win - went from hero to zero as he missed the crucial penalty in the shootout.
The summer exhibition period has not been kind to Sheffield United, who enter their opening Championship clash having lost three of their last four friendlies away to Scunthorpe United, Mansfield Town and Barnsley, but victories over Lincoln City, Casa Pia and Burton Albion did come their way.
While Watford have developed a penchant for opening-day performances, Sheffield United can only boast one win from their last eight such matches - losing the other six - and both meetings between the sides in the 2019-20 Premier League season ended all square.
Watford pre-season form:
Sheffield United pre-season form:
Team News
Only midfielder Imran Louza should be absent for Watford on the opening day, with the former Nantes man yet to recover from a knee injury, but the Hornets are otherwise fit and raring to go.
A mass exodus occurred at Vicarage Road in the wake of their relegation, but Edwards has so far managed to keep hold of Emmanuel Dennis, Ismaila Sarr and Manchester United-linked Daniel Bachmann.
New signing Mario Gaspar has had little time to get acquainted with his new teammates and may therefore not be involved from the off, while Rey Manaj and Vakoun Issouf Bayo are ready to make their mark in the final third.
In contrast, Blades boss Heckingbottom must work around a number of injury absentees, as Jack O'Connell, Jayden Bogle, Adam Davies and Tommy Doyle are set to watch this one from the sidelines.
It remains to be seen if Billy Sharp and Oli McBurnie will be cleared to play, so Rhian Brewster ought to lead the line after building up his fitness in pre-season, potentially alongside Reda Khadra.
Ciaran Clark and Anel Ahmedhodzic can expect to be handed their competitive debuts for the visitors, and Sander Berge remains on the books at Bramall Lane and should start in the engine room.
Watford possible starting lineup:
Bachmann; Ngakia, Kabasele, Cathcart, Kamara; Cleverley, Kayembe, Gosling; Sarr, Pedro, Dennis
Sheffield United possible starting lineup:
Foderingham; Clark, Egan, Ahmedhodzic; Baldock, Norwood, Fleck, Berge, Norrington-Davies; Brewster, Khadra
We say: Watford 1-1 Sheffield United
The harmony has not been disrupted too much in either squad this summer, and keeping the likes of Joao Pedro, Sarr and Dennis on the books spells goals for the Hornets.