Jurgen Klopp is unsure how long he will be without the services of the injured Joel Matip, conceding that he could miss a month of action.
Matip has picked up a few injuries in recent weeks, with the latest an adductor muscle problem sustained ahead of Saturday's 5-1 win over Brighton and Hove Albion.
The Cameroon international missed that triumph as a result and will also definitely be out of Wednesday's Champions League meeting with Spartak Moscow - a game Liverpool need to win to make absolutely sure of winning Group E.
Klopp was eager to reassure fans but acknowledged that he does not actually know the full details.
"He has hurt his muscle," Klopp told Liverpool's official website. "I don't know how long exactly he'll be out, but he's definitely not playing Wednesday.
"A month? No, I don't think so. But as always, it's possible. We have to wait.
"But it's possible that it will be shorter. We will see."
Emre Can and Georginio Wijnaldum had to fill in at centre-back in Matip's absence on Saturday and Klopp was impressed with how they coped.
"Emre needs to do that [play centre-back at times], like Gini [Wijnaldum] can do that," Klopp said. "They have to do it, we don't have anybody else.
"I enjoyed it. It was like 'wow, interesting'. We had 20 minutes in training and then we spoke for a little bit in the team meeting before the game again about it.
"But it's not long. It was clear it wouldn't be perfect, but the boys were ready to cope with the difficulties of the new system. They did really well."