Watching from the halfway line, they could barely hold each other up.
It is a wonder some of them had the stamina to make the long walk to the winning penalty spot. This was a triumph of willpower, a victory for indomitable spirit.
You know what Jurgen Klopp calls this collection of players, you don’t need reminding. And their mentality is, indeed, for want of a better word, monstrous.
The physical needle might be heading towards the red but the psychological tank is still full. Hey, who knows? Such has been their remarkable will to keep on winning, the quadruple might yet still be on. Maybe they should send a pep talk to the West Ham dressing-room ahead of Sunday’s match.
The heroes of the shoot-out hour were Alisson - for saving Mason Mount’s kick - and Kostas Tsimikas, for converting the winning penalty. But this was a success built on an insatiable desire not to get beaten, to win at all costs.
Klopp has instilled it into their psyche and this is what drives this Liverpool team. This is what will drive it in the final two games of the Premier League season, no matter how unlikely eventual triumph seems.
And this is what will drive them in Paris at the end of the month. Even if Manchester City do wrap things up, a Cup treble would still be a quite fantastic achievement for this squad.
Away from its obvious brilliance, the indefatigability of this Liverpool team has been remarkable, their energy levels, at times, bordering on the freakish.
Can Liverpool still win the quadruple this season? Have your say in the comments!
But it is not just tirelessness that has been a key element of their campaign, but durability. And there is no player in the Premier League more robust than Mohamed Salah.
His availability over the course of his Anfield career has been astonishing - he has been ruled out of only three matches in almost five seasons, and one of them was through Covid. Yet even Salah has been looking, by Liverpool standards, a little jaded of late.
And maybe that hint of fatigue was a contributory factor to Salah picking up the injury that forced him out of proceedings just after the half-hour mark.
After exhausting schedules for both teams this season, it is a wonder a few more did not lose a physical battle in an attritional match and high temperatures. In fact, it was to their credit they produced what was, by FA Cup final standards, a relatively compelling spectacle.
Liverpool fans jeering Abide With Me, presumably because they initially mistook it for the National Anthem, set the tone - entertaining but with the odd mistake. Indeed, that summed up the contribution of Luis Diaz, who appeared to have the freedom of the park for most of the first half.
Diaz is another high-speed dynamo but his finishing was awry and his option-choosing far from flawless. For sure, he is an extremely exciting signing and a mouthwatering prospect but no-one should be going overboard about him just yet.
Let’s see what he does over the course of a whole season. And his presence does not mean the need to extend the contracts of Salah and Sadio Mane is any less essential.
With Mane not at his mercurial best and Salah off injured, there was a slight lack of ingenuity across the forward line but the pace and directness of Diaz always caused Chelsea problems.
The Colombian looked as fresh late in normal time as he did when Craig Pawson first blew his whistle. In fact, Diaz was unlucky not to settle matters in normal time but he was one of two Liverpool players to hit a post, Robertson being the other.
Marcos Alonso also sent an effort against the goal-frame and that typified the nature of the match. It was exciting but quite noticeably shy of quality in respective penalty areas.
That was until Alisson and Tsimikas kept their cool and kept Liverpool hopes of the quadruple alive.
