The Blaugrana were certainly the team in form, and the win probably won't have come as that much of a surprise to many.
But the manner in which it was achieved and the final scoreline left a bad taste in Valencia supporters' mouths and left Neville having to face the music both from supporters and the media.
It was a seven-goal margin, but in truth it could've been 10 or 12, such was Barca's dominance from start to finish—a genuine men against boys exercise for the most part. BBC Sport's Andy West agreed with that sentiment:
How Los Che manage to recover from such a bitter blow is anyone's guess. Neville had already noted in the wake of the Barca defeat that the following league match at Real Betis was a must-win game. He told reporters, per Sid Lowe of the Guardian: "Let's be clear: We must deliver."
Deliver they did not, ramping up the pressure on a manager who can still only point to four Copa del Rey wins as his successes during his time in the hot seat.
In the wake of that defeat, Alvaro Negredo noted post-match, per Joe Wright of Goal.com:
The team are hurting; it is a very difficult situation for everyone. It's sad, but it's the reality. The coach makes his choices and they have to be respected. He also wants us to get out of this situation.
We have had good games that we haven't won, and others that have been disappointing – such as the one against Barcelona.
Pride is the best that Valencia can play for in this second leg—pride that the locals as well as the management team will demand.
They'll certainly be looking for a reaction to their appalling last home league loss—their first since 2014—to Sporting Gijon.
Whether they'll get it will depend very much on how Luis Enrique sets his stall out on the night.
Per Eduard Gangoso of Barcelona's official site, Barca's manager noted the strangeness of the tie, telling assembled media:
It won't be an easy game, and it will be a bit strange after the result of the first leg. But it's a good test for us, because it's the chance to show that we are still competitive in any situation.
We need to forget about the first leg result and go and play to win like we always do. We have no idea what kind of Valencia we'll be up against.
Neville can at least be spared the threat of Lionel Messi doing more considerable damage. The Argentinian maestro has had minor surgery on a kidney complaint and, per Albert Masnou of Sport, will return to training on Thursday.
Date: Wednesday, 10 February
Time: 8:00 p.m. GMT/3:00 p.m. ET
Venue: Mestalla Stadium, Valencia
TV Info: Not available in the UK/beIN Sports 1 (US only)
Valencia have absolutely nothing to lose in this game, and an attacking 4-2-3-1 formation from Gary Neville can be expected.
It gives the manager the comfort of two holding midfielders to protect the defence when required, and it also gives support to lone wolf Negredo.
It could be a long night for the ex-Manchester City man if he doesn't get the right service from his wide players Sofiane Feghouli and Denis Cheryshev, but there is some hope of success particularly down the right side of Barca's 4-3-3 as Enrique rests three of his normal four in defence.
Jeremy Mathieu, Thomas Vermaelen and Aleix Vidal join Gerard Pique with Marc-Andre ter Stegen looking for another clean sheet for the visitors.
Sergi Samper is given the chance to impress alongside Barca B colleague Wilfrid Kaptoum and Arda Turan. Along with Vidal, the Turkish international should get the full 90 minutes here.
Andre Gomes could cause problems centrally if not closed down, while Dani Parejo won't need to be asked twice to meander forward if the opportunity presents itself. Enzo Perez can hold the fort while the former is so doing.
Mat Ryan and his defence of Antonio Barragan, Ruben Vezo, Aymen Abdennour and Jose Gaya have the unenviable task of trying to stem the Blaugrana tide for the second week in succession.
Player to Watch
In the darkest hours you need a ray of light and of hope to guide you through. Andres Gomes is that man.
While all around him appear to be losing their heads, Gomes is a beacon for Neville and Co. The midfielder has continued to produce, and it's a great shame that many of his team-mates don't seem to be on his level.
The midfielder isn't frightened to put his foot in if necessary, and his boundless energy ensures he'll keep scrapping away until the final whistle.
He might find some more space is available to him on the night as he looks to ensure Sergi Samper doesn't have quite the influence of his contemporary Sergio Busquets.
Although "Busi" played only 20 minutes against Levante, there's simply no need for Luis Enrique to count on him here, despite a continued excellence in the defensive midfield role.
This match, however tough it ends up for Barca, will at least give Enrique some more clues as to whether Samper is worthy of a more regular employ at this level.
To do so, he has to shut down Gomes at every opportunity.
Once he gets into his stride, the Valencia midfielder is difficult to shake off and with willing runners on either side, Gomes could be pivotal to the hosts' aspirations of a victory—however hollow.
Aymen Abdennour will absolutely need to be on his mettle here for fear of another embarrassment. One that neither he, the coaching staff or the club can afford.
Whether it's Suarez or Neymar bearing down on the defence, the Valencia centre-back needs to offer stiff resistance.
Suarez just can't stop scoring at the moment, and this game gives him another opportunity to deliver.
In the form of his life and ahead in the La Liga race for the Pichichi, putting the icing on the cake as Barca march on to another final will spur on the Uruguayan—a player who lives for goals.
Under the circumstances, the best Abdennour can hope for is to curtail Suarez's movement across the lines, stopping him from opening up the spaces for others to move into. And indeed stopping the striker from getting shots away in the central areas.
Keeping a solid but mobile shape, in much the same way Valencia approached the league game here, is all- important and could pay some dividends.