Liverpool have been dealt another blow in defence as Fabinho suffered a hamstring injury against Midtjylland on Tuesday night.
The Brazilian has been a vital member of the Liverpool squad in recent weeks, filling in defence for the injured Virgil van Dijk, who is ruled out for at least the majority of the 2020/21 season.
With Joel Matip also sidelined, the Brazilian has stepped up to the mantle and put in some exemplary displays at the back.
But now Liverpool may need to navigate the next few games without their newfound centre-back after he suffered a hamstring injury in the first-half against Midtjylland.
Speaking after the game, Klopp confirmed Fabinho's injury but was unable to offer a prognosis at this time.
"It's exactly the last thing we needed. What can I say?" Klopp told BT Sport.
"I don't know [right now]. He felt his hamstring so that's not good. He didn't feel too much - he could have played on but he couldn't sprint, which doesn't help in that position obviously.
"We will see. We have to do a scan and then see, but right now it's not good."
Fabinho pulled up as he was running back on a Midtjylland counter-attack, suggesting he had unexpectedly tweaked a muscle.
He was able to walk off the pitch and didn't look to be in severe pain, but regardless a hamstring injury could mean anywhere from a few days to several weeks on the sidelines.
Liverpool can ill afford to lose Fabinho, even for a few weeks, with their options beyond the Brazilian extremely limited.
Youngster Rhys Williams came on to replace the 27-year-old and could be relied upon during any potential absence for Fabinho.
Billy Koumetio, Sepp van den Berg and Nathaniel Phillips could also be called upon, while further left-field options could include Gini Wijnaldum, who turned out in a back-three for the Reds against Brighton a couple of seasons back.
Liverpool have three fixtures remaining before the November international break. West Ham's visit of Anfield is followed by a clash against Atalanta next week, before the Reds travel to the Etihad to take on Manchester City.