During the first half of Tottenham’s 2-0 win at Huddersfield on Saturday, Jan Vertonghen crumpled to the turf gripping the back of his leg.
He stood up and hobbled before Eric Dier urged him to go to ground and await treatment. Vertonghen – along with Belgium team-mate Mousa Dembele – then failed to appear for the second half.
He will already be without Dele Alli – injured during international duty and re-injured before this game – while Christian Eriksen missed out in West Yorkshire with an abdominal injury of his own.
Pochettino likes to work with a relatively tight squad but these knocks leave him facing depleted numbers before Barca come to town.
The Spurs coach had set his team up against Huddersfield in a 5-2-3 formation, with the pace of Son Heung-min and Lucas Moura allowing Spurs to counter clear when possession broke down. That’s how it might be in London midweek when Barca have plenty of the ball.
It’s not like Spurs to be beaten in the possession stakes but Huddersfield had more of it here. Granted, the ball spent as much time in the sky as it did on the grass but Spurs struggled for a foothold.
The 5-2-3 might have been a specially selected strategy with the intensity of Huddersfield in mind, but the personnel within it were the best Pochettino could muster in the circumstances. Harry Kane scored twice to carry home the three points. Pochettino knows he can't do without the England captain. Without him, Spurs don't look the same.
The only player he rested here was Erik Lamela, who didn’t get off the bench. Pochettino – after a fruitless summer transfer window – simply doesn’t have much room to manoeuvre when it comes to rotation.
That is in contrast to his Barcelona counterpart, Ernesto Valverde, who is now under severe pressure. The succour of last season’s domestic double has already worn off. Barca have watched Real Madrid cart off the last three Champions League titles and much of the early season message to the media has been about the focus on continental success.
Domestic glory is almost as taken for granted as Lionel Messi’s brilliance and the focus now is on getting it right in Europe. But their standards are slipping badly. Spurs will be taking on an underperforming and out-of-sorts Barcelona; if it wasn’t for those new injuries then they might see themselves as genuine favourites for Wednesday.
Unlike Kane, Messi and Sergio Busquets were left out of the side to face Athletic Bilbao - and Barca were punished. Valverde is a coach in a bind. His first season at the club was extraordinary and he should have been among the nominees for FIFA’s Coach of the Year award last week.
They talk in American sports of the 'sophomore curse'; the inability to follow a stunning debut season with anything like the same consistency. That would appear to be where Barca are at with their coach.
He will need to rotate his squad for a long season ahead but he is utterly dependent on his favoured XI and Messi in particular.
It’s been a bad, bad week for Barca. They are three games without a win in La Liga after two draws and a defeat. They are faltering – collectively and individually – and the only aspect keeping them on the requisite level is Messi.
In that regard, it was a strange decision from Valverde to leave him out. Barca needed to bounce back after their midweek loss to Leganes; surely the most productive thing to do would be to play Messi, win convincingly and ensure confidence is high going into Wednesday. Instead, Valverde has invited more criticism and more pressure.
The prospect of a game without him in the line-up is enough to make Barca blood run cold, let alone that Messi-less future which one day will stretch out before them.
He assisted Munir for the equaliser against Athletic and could conceivably have had a hat-trick for himself.
But Barcelona might feel slightly off the hook as a result of those Spurs injuries by the time they turn their focus to European matters.
Dier switched to centre-back after the Vertonghen injury but his distribution remains amiss and he showed a tendency to concede fouls at the edge of the box. A free-kick taker the quality of Messi will do more damage than Chris Lowe did here.
Victor Wanyama and Harry Winks took up the central midfield position in the second half, but in truth no Spurs combination got to grips with the game in there. Huddersfield were too aggressive, too snappy, for the pace of football they wanted to play.
A peak Barca can do similar, even if that prospect seems remote given their troubles at the moment.
It’s set to be a fascinating game at Wembley and could rival Liverpool's tussle with Paris Saint-Germain for tie of the group stage. There are flaws on both sides and yet both are possessed of enough attacking talent to keep the other worried. Messi could well be the deciding factor but his form in England is ordinary by his own high standards and he’s without a goal away from Camp Nou for the last five months.
Spurs went toe-to-toe with defending Champions League holders Real Madrid this time last season and dismissed them convincingly. It was a win in Europe that gave the players belief in their coach and his methods. It was also a brutal wake-up call for Zinedine Zidane and his team who did not get their act together until well after Christmas.
Valverde will get nothing like that kind of time, despite his trophy haul last season. He will be hoping Messi’s rest was worth it.