Watford 1 Sheffield United 0: Hornets sting Blades on opening night at Vicarage Road

But whilst the likes of Emmanuel Dennis and Ismaila Sarr looked every bit the top-flight footballers they no doubt hope to be again before the transfer window closes on September 1, it was referee Josh Smith who opened the door for Sheffield United to start their new season with a 1-0 defeat.

Whatever other changes Blades supporters are looking for in the window, a bit more help from Lady Luck would not go amiss. Not that Watford’s opening-night victory was undeserved or that fortune was the only reason they scored.

Despite an angry reaction which put manager Paul Heckingbottom’s name into his notebook, it would be completely wrong to dump all blame for it on the referee, who had shown leniency when John Egan bundled Joao Pedro over minutes earlier because the Blades had plenty of opportunity to deal with a counter-attack and failed to. But he certainly did not help.

When Smith found himself in the line of a corner pulled back for John Fleck he managed to get out of the way it time but it seemed to discombobulate the midfielder, who had only minutes earlier lost team-mate Enda Stevens to injury. His shot hit a defender and from there Watford counter-attacked with a pace and precision the away side could not deal with, Sarr crossing for Pedro to score.

Take that out of it, and the Blades could have been pleased with the way they kept a speedy, skilled Watford side at bay. The problem is, you cannot take that out of it.

The start of the new season has brought fresh problems for the Blades, without Chris Basham thanks to a hamstring injury and, after a weekend training session, fellow centre-back Jack Robinson. With Anel Ahmedhodzic seeing out a suspension picked up as an on-loan Bordeaux player last season - something Heckingbottom only found out on Thursday - it left them light at the back.

With Billy Sharp and Rhian Brewster only considered fit enough for the bench and Oli McBurnie not even up to that, it was a team-sheet that screamed of the need for reinforcements but then you get a lot of those when teams are starting their campaigns a month before the transfer window shuts. Watford had an XI made up entirely of players who appeared for them in last season’s Premier League.

The disruption seemed to affect Clark the most, the left-footer making his debut on the opposite side of the back three to the one he had presumably begun the the week training on.

Whether it was that or just the quality of Dennis, the Newcastle United loanee from had a difficult competitive debut, the Nigerian beating him before playing in Ismaila Sarr to hit the side netting after five minutes.

John Egan, reliable as ever, came across to deal with Dennis after the forward got in front of Clark to take a pass.

So it was no great shock Clark was the first player booked, for blocking Dennis as he tried to accelerate past him.

In fairness, Clark got across well to snuff out the danger when Ken Sema threatened to run through just before the half-hour, but he was sacrificed in a 69th-minute triple substitution.

For all that, the only save of note Wes Foderingham had to make was a largely photogenic one, catching Pedro’s header.

The Blades front two of Daniel Jebbison and Iliman Ndiaye looked lively and in tune in the rare moments their team-mates could involve them.

Fighting off Kamara left Ndiaye without the balance to make the most of his strike partner’s flick-on but Jebbison ended the half with his best chance as Sander Berge and George Baldock sprang a counter-attack. Daniel Bachmann tipped the curling shot over.

Watford came out strongly for the second half and deserved their lead.

Heckingbottom tried to change things but giving Rheda Khadra his debut at centre-forward only to drop him into the hole to accommodate Sharp nine minutes later hinted at scrambled minds.

As well as the changes, the flow of the game was disrupted by a brief pause in the 72nd minute - not that it mattered in the great scheme of things.

The raucous away end had been trying to get the match paused for a couple of minutes - two supporters running on and the rest chanting “Stop the game!” after a female fan collapsed with what was believed to be an allergic reaction 72 minutes in. After nearly 20 minutes of treatment, she was helped out of the stands.

For all the strikers introduced, none were at the far post when Egan headed an 82nd-minute free-kick there but Watford had a chance too, Foderingham denying substitute Rey Manaj.

Watford: Bachmann; Kabasele, Sierralta, Cathcart; Kamara, Cleverley, Kayembe, Sema; Sarr (Manaj 81), Dennis; Pedro (Gosling 87). Unused substitutes: Ngakia, Troost-Ekong, Asprilla, Bayo, Hamer.

Sheffield United: Foderingham; Clark (Osborn 69), Egan, Norrington-Davies; Baldock, Berge, Norwood (Khadra 69), Fleck, Stevens (Lowe 55); Ndiaye (Sharp 78), Jebbison (Brewster 69). Unused substitutes: Amissah, Gordon.

Referee: J Smith (Lincolnshire).