Liverpool are sweating on the fitness of centre-back duo Dejan Lovren and Joël Matip for their trip to Leicester City in the Premier League this Saturday.
The Reds make their second visit to the King Power Stadium in four days, having lost 2-0 to the Foxes in a Carabao Cup third-round clash on Tuesday night.
But they could be without their two first-choice central defenders due to knocks, while midfielder Emre Can had been considered a doubt but trained with the rest of the Liverpool first-team later on Thursday.
Lovren has not featured in any of Liverpool's last three league games, though was involved in a European tie against Sevilla earlier this month, while Matip and Can picked up minor problems in a league draw at home to Burnley last weekend.
In his pre-match press conference, Klopp told reporters that Lovren's injury is "nothing major" but has been "enough to keep him out of two games."
The German explained: "He is not in training so far so that means he is also a doubt for the weekend, which is not too cool. It's the same with, but completely different [injuries], Joël Matip and Emre Can."
Klopp said that the duo "have little bits from the last game" and that it is "not sure at the moment" whether they will be available to face Leicester or not.
"Reds will be ready for Leicester test whoever plays"
Even Klopp is without his two preferred centre-halves, he is confident that Liverpool are capable of exacting revenge of sorts on Craig Shakespeare's side for their mid-week cup exit.
He insisted that if both are out injured, then it will be "the third game in a row for Ragnar [Klavan] if he plays again."
Klopp also said that Joe Gomez "made a game in the centre-half position" earlier in the week, adding: "So then we would have to see how we can manage it if it was to be like this [without Lovren and Matip]. I don't hope it is like this."
He added that Trent Alexander-Arnold would play "again at full-back" and then again "three days later" in a Champions League group stage clash at Spartak Moscow "because Joe is suspended."
Klopp joked that such dilemmas represent "a normal day for a football manager", insisting that he and his staff will "have to see what we can do."
"Until I know it [the team selection] is not verified how it is exactly, I have to wait and we have to train with the boys," he continued. "Then we will prepare for the game and we will see until Saturday."
Klopp noted that there is still time for players to prove their fitness, calling it "a normal challenge" that they might be without first-choice defenders.
He said: "It's not that it's worse or better than the other situations. It's how it is. Players can get ill overnight and then you have to make another plan. That's why we prepare pretty much everything when we know who we can use.”
Elsewhere midfielder Adam Lallana returned to outdoor running on Thursday as he continues his rehabilitation from a thigh injury sustained in pre-season last month.
The England international has not yet featured in a competitive fixture for the club this season.