Arne Slot was left to count the cost of Liverpool's chaotic 2-1 win at nine-man Tottenham after Alexander Isak's rare goal was followed by a potentially damaging injury.
Isak fired Liverpool into a second-half lead in north London with a clinical finish, only to limp off moments later after being injured by Micky van de Ven's failed attempt to stop him scoring.
The Sweden striker's third goal for Liverpool since his British record £125 million ($166 million) move from Newcastle on transfer deadline day had offered hope that he was finally set to live up to his hefty price tag.
Instead, Reds boss Slot now faces an anxious wait to determine how long the 26-year-old will be sidelined with his ankle problem.
Slot would only say that Isak's injury was "not a good thing".
It could not have come at a worse time for fifth-placed Liverpool after Egypt forward Mohamed Salah's departure to the Africa Cup of Nations and an injury to Dutch winger Cody Gakpo.
Adding to Slot's fitness issues, Isak only came off the bench at half-time after right-back Conor Bradley was injured.
Although Liverpool are unbeaten in their last six games in all competitions -- winning three in a row -- the brief flicker of promise engendered by the sight of Hugo Ekitike, Florian Wirtz and Isak combining for the opening goal was quickly snuffed out.
The trio cost around £300 million to bring to Anfield in the close-season, with only Ekitike, the least expensive of the group, living up to the hype during the Premier League champions' troubled first half of the season.
French striker Ekitike maintained his strong start to life with Liverpool by heading their second goal against Tottenham.
But even then, Liverpool made heavy weather of it as Tottenham, already down to 10 men after Xavi Simons' first-half dismissal for a crude foul on Virgil van Dijk, pulled one back through Richarlison in the closing stages.
Tottenham captain Cristian Romero's stoppage-time dismissal for a needless second booking after he kicked Ibrahima Konate let Liverpool off the hook just as they looked set to blow the lead in a frenzied finale.
Breathing a sigh of relief, Slot said: "A good goal (for Isak), assisted by Florian Wirtz, and I said last week already players are getting better, the team is getting better.
"I thought to be honest with nine, we will probably be able then to keep them away from our goal, but it looked as if we were down to nine and they were on 11 because it was attack after attack after attack.
"Again, it wasn't perfect, especially not in the last 10 minutes but in the meantime, we pick up points and I see the team developing in a way I like to see."
Meanwhile, under-fire Tottenham boss Thomas Frank blasted referee John Brooks.
Frank was furious with Simons' red card -- which was upgraded from a booking after a VAR review -- and the failure to disallow Ekitike's goal for a push on Romero.
"I don't like this as a red card. I think the game is probably too big to say gone, but for me it's not reckless and it's not exceptional force," said Frank, whose side are languishing in 13th place.
"He is chasing Van Dijk. He is trying to put pressure and then he changes direction. Unfortunately, his foot is on Achilles. You can say 'Ah, you need to be smarter, don't do it and all that' but so are we not allowed to have physical contact anymore?
"The second goal is a mistake from the referee. There are two hands in the back. I don't understand how you can do that.
"I think that was the biggest mistake in my opinion and from VAR but apparently that was not enough."
