Keita’s career at Anfield has failed to truly take off with various injuries limiting his time on the pitch and he lasted just 53 minutes before limping off and being replaced by Neco Williams.
And after the match, Klopp revealed the midfielder will now be assessed by the medical team to determine the severity of the injury, amid a hectic fixture scheduled.
He said: “He felt his hamstring and was not able to play on, otherwise he would have stayed on the pitch.”
Keita will be joined on the injury list by Xherdan Shaqiri, who picked up a muscle issue on international duty with Switzerland.
Klopp added: “Shaq, how I know it, he had a muscle injury with the national team which he didn’t really realise.
“Now he trained with us, we gave him a day off and then he came back and was involved in the session, but was not fully involved and all these kind of things.
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“He just did a little bit, after that he felt a little bit. Then we did a scan and they found he has an injury from five or six days ago.
“Nobody knew about that, not even Shaq knew about it, but that’s how things sometimes are and so he was not able to be involved.”
But after testing positive for coronavirus last week, Mohamed Salah will return to training on Monday and be in contention to face Atalanta in the Champions League on Wednesday.
“That’s what I’ve heard, yes, it [was] negative today,” Klopp said. “I think he is from now on pretty normal in testing. Tomorrow we have the UEFA testing for the Champions League and I am pretty sure he will be in that.
“He can now train with us tomorrow, that’s it. He will have two tests in the next two days, so, yes, he will be tested like all of us.”