When he's been at the hub of a great European campaign, Unai Emery has rarely paid too much mind to the league campaign going at the same time. Ask Sevilla fans. Yet this weekend, it felt like a limit might have been reached.
Villarreal went down to a 2-1 defeat at Alavés, fighting to stay afloat at the foot of La Liga. That little bit of extra intensity that the strugglers were able to inject into proceedings made the difference, despite a second-half comeback from the Yellow Submarine in a match they really could have done with winning as they aim to qualify for Europe next season, albeit in a competition a tier below (pausing for a second the idea that they could still, theoretically, win the Champions League).
Emery spoke afterwards of his team's "physical and emotional exhaustion," which underlined exactly how much the first leg against Liverpool at Anfield had taken out of them after a long season. It was particularly notable given the fact that the coach had affected eight changes to his starting line-up, and that they had followed up knocking out Bayern Munich by putting together successive Liga wins.
It all went to underline exactly what an Olympian task facing Liverpool is at the moment. In 25 games since mid-January Jürgen Klopp and company have failed to win just three - home second legs against Inter and Benfica in the Champions League which didn't hinder their progress following handsome away wins, and that titanic stalemate against Manchester City at the Etihad.
No wonder Villarreal, already pushed to the limit with successive Champions League ties with Juventus and Bayern which would require the best of far better funded European names, might be feeling the exertions of the season catching up with them. It also reminds us that criticism in sections of the English media of their defensive approach at Anfield was unreasonable and unrealistic.
First leg showed Villareal's qualities
Even if Emery and his charges didn't get the result they wanted last week, they showed a lot of the qualities that have got them this far, beyond all expectation.
They were gnarled, organised and showed their poise in refusing to collapse - as many teams would have - after conceding twice in the space of a couple of minutes to Liverpool, who must have smelled blood.
The question is how they can make The Reds uncomfortable by genuinely threatening them. A replica of the first leg, first half performance against Bayern, in which they thrust the unsuspecting German champions into a spin cycle, would be just the job - pressing, closing space, and getting extra players forward from unexpected areas, like Francis Coquelin. There is at least hope of a result on the night, with Liverpool not winning the return leg of each previous knockout round after an authoritative win in the opener.
The big plus is that Gerard Moreno will be available for this return after a hamstring problem and if he's firing, that would be a game changer for Villarreal.
He is not just a great goalscorer, but a genuinely great reader of the game in the final third.
Given the nature of his injury it is a risk but if ever there was a game to take a punt on your star player's fitness, then this would be it.
Hoping for all this to fall into place is asking for a lot, but hope - and hard graft - have got Villarreal this far. Their fans, and neutrals, must hope they have enough in the tank for one last offensive.