Ahead of Valencia's third -- and most important -- meeting with Athletic Club Bilbao this season, one of two difficult questions facing Mestalla manager Gary Neville is easy to answer, while the other carries more risk.
While Neville's early reign was plagued with injuries, criticism, failure to win a Liga match and increasing discontent from the ferocious crowd in Valencia, there was one significantly obvious thing:
As soon as he was regularly able to field three of his squad's key players -- Diego Alves, Sofiane Feghouli and Javi Fuego -- then both performances and results were going to improve.
Training was good and the squad's mood was significantly better than under Nuno Espirito Santo as Neville, gradually, had an impact on the intensity of his players' mentality.
Throw in the return of top players, as well as the addition of know-how in the form of newly-hired coach Pako Ayestaran and, sooner than later, there was going to be a positive effect. Sure enough, most of those players are now back and Valencia are not only competitive, they've begun to rack up wins.
But Sunday night's defeat at home to Atletico Madrid underlined that the whole process has been two steps forward and one back.
It wasn't a coincidence that league victories returned simultaneously with the agile, split-second reactions provided by Alves, who has added savvy, talent, cat-like reflexes and assurance to Valencia's seemingly endless attempts to keep a clean sheet in La Liga. (To find the previous one, you have to go back to October and a derby win against Levante.)
But then, in his fifth game since coming back, there was catastrophe.
Nine months out takes a toll and Alves was absolutely at fault for two of Atleti's goals in Valencia's calamitous 3-1 home loss having made, in between them, one of the most fabulous, jaw-dropping saves you'll ever see.
So, in theory, Neville had a big, big decision to make. Should he coach drop Alves for his errors and accept that he needs more hours on the training ground to reach excellence?
Or should he stoutly say to the Brazilian: "You're the best keeper in my squad, you're my club captain; sort your act out now, but you've still got my faith."?
Not an easy choice.
Where Neville gets off lightly is that he'd settled on a policy of rotating keepers. Mat Ryan, the terrifically-talented Australian international, played in the two Europa League Round of 32 thrashings of Rapid Vienna and was already scheduled to be between the posts against Athletic at the San Mames this week.
So Alves, for the moment, neither needs to be either immediately dropped or immediately reassured, though he must work blindingly hard in training this week and prove that it was an aberration when he cost Valencia a draw against Diego Simeone's side.
The other concern for Neville relates to Javi Fuego. He is Valencia's Sergio Busquets: The organiser, the ball winner, the guy who protects midfield runners, who ensures that they are covered.
Without him Los Che's midfield has been paper-thin, pushed around, less organized and much less physically aggressive.
The 12-goal, five-assist career-high excellence of Dani Parejo last season pertained greatly to having the perfect player, Fuego, next to him. The more Parejo jaunted forward to shoot, create goal assists or draw fouls around the edge of the box, the more that Fuego protected him.
Apart, Parejo has looked as if he has nerves of glass this season and an alarming lack of ferocity. Together, though, equilibrium.
However, at 32 and having only recently returned after a six-week absence, there might easily have been a temptation to rotate Fuego; to let him rest and be ready for next weekend in the league.
And this is where the risk comes in for Neville.
Defeating Rapid Vienna was a far more impressive achievement than Valencia have been given credit for. At the time of the tie the Austrian side were equal top in their league and, in Europe, had knocked Ajax out of the Champions League qualifiers and beaten Villarreal in the Europa League group.
No mugs, then, yet they were utterly destroyed -- 10-0 on aggregate -- by a Valencia side that featured Fuego in the engine room providing, if you will, the "buckle" to the "swash" of others. (Incidentally, two weeks Fuego did not play at the Camp Nou, where Valencia were positionally unsound and ragged in their reaction to the attacking moves of Barcelona, who won 7-0)
Valencia winning the Europa League might seem improbable but, in football, you never know. And as such there's so much at stake, not least improved financial rewards and the prospect of direct entry into the Champions League if the unlikely happened.
Thus it's an absolute imperative that Valencia defend with organisation, intelligence and brains in the first leg against Athletic Club and keep the tie alive until the second leg at Mestalla.
To do that, they must quell the threat that is Athletic's Aritz Aduriz. The 35-year-old already has 36 goals in all competitions this season and is as clever, confident, assured and successful as he's ever been.
He and Fuego share certain tendencies.
Aduriz was a cross-country skier as a child and so knows a bit about rough conditions, extreme stamina, hard mentality and pushing your will-to-succeed to the limits. If you don't believe that's linked to his long term excellence, then you're on your own.
Meanwhile, given free time, the equally hard-as-nails Fuego and his brother will set off on "cross-running" marathons across mountain ranges, covering anything up to 100 kilometres, losing themselves in nature and either sleeping in tents or basic hill-top "hostals."
It reminds of Luis Enrique, another Asturian who hails from the same tough, mining country. The current Barcelona manager used to fill his free time by running across the Sahara -- marathon after marathon, despite the fact that it left his feet in bloody tatters.
Thus, it is right up Fuego's street to lead Valencia at a difficult time, when fans and media sway between backing and barracking, and take the club deep into enemy territory in the Basque Country.
"My parents taught me a series of values -- work, effort, humility -- which have served me very well both in my football career and life generally" he explains. "And my brother Juan is the one who taught my passion for the mountains and running across them. It is a very tough sport physically but much more so in terms of your mental strength. Whatever happens, when times are really tough, you never ever give up."
Rotation is important, particularly in a team like Valencia where youth and experience don't have a "middle class" of players to knit their efforts.
But if I were Neville and wanted to keep my team alive in the Europa League then, even if I rotated my goalkeeper, I'd keep the experienced mountain-running midfielder in my team.