The eyebrows raised and the air was inhaled when Liverpool's team sheet dropped out of the blue just after 4pm.
Eyes scanned across the list of 11 men selected to contest the Reds' first-ever competitive game in Doha. One key name was conspicuous only by its absence.
Virgil van Dijk was nowhere to be seen. Cue dramatic music.
This marked the first game Van Dijk has been unavailable for selection for this season, having missed the Carabao Cup games at MK Dons, Arsenal and Tuesday night's foray to Villa Park through rest only.
Monterrey vs Liverpool LIVE - FIFA Club World Cup action and reaction
Here, in Qatar, however, the Dutchman's official absence was put down to illness.
It could scarcely have come at a worse time for Liverpool and Jurgen Klopp, who continues to navigate through the choppy Decembers waters with one centre-back problem after another.
It's been close to two months since Joel Matip last featured in a Liverpool game. His most recent run-out came back on October 20 at Manchester United.
His knee injury has persisted to the point where he was left out of the travelling 20-man squad all together for the Club World Cup. It is difficult to envision a scenario where he returns to full fitness in time for that crucial clash on Boxing Day at Leicester City.
Meanwhile, Dejan Lovren continues to struggle with his own issues.
The Croatian was withdrawn in the first half of the 3-0 win at Bournemouth on December 7 before once more pulling up ahead of the hour mark in the 2-0 triumph in Salzburg three days later.
Lovren was visibly wincing as he hobbled out of the Red Bull Arena and will be sidelined for a number of games with a hamstring complaint.
It has left Liverpool with the most threadbare of centre-back options, given Fabinho has been left on crutches by an ankle issue, and the illness to Van Dijk only deepened what has now become a crisis for Klopp.
Against Mexican side Monterrey Rayados, Jordan Henderson was able to utilise his ample experience and know-how to negotiate a way through the game at little detriment to Liverpool's overall aims of winning this competition for the first time in their history.
Against a side with more quality, though - someone like Saturday's fellow finalists, Flamengo, for example - Liverpool will have a real issue on their hands. They certainly won't want such a centre-back shortage when Premier League duties resume later this month.
“We will not sign a centre half because of injuries," Klopp said earlier this month. "That is the world outside who thinks we are short and we have to do it - but afterwards we would have six centre halves and that wouldn’t make a lot of sense."
This particular result is unlikely to have changed his mind, but would a proactive approach to this situation in the January transfer window really be so harmful?