Not only was a 3-1 defeat to Brentford a big enough blow for Liverpool on Monday night, but on top of that came an injury concern for Van Dijk.
After clocking more minutes than any other player in the first 26 games, the Dutchman was forced off at half-time in west London, before visiting a specialist on Wednesday.
Speaking in his pre-match press conference on Friday, Klopp revealed that it was a “harsh diagnosis” and his No. 4 is likely to be out for “more than a month.”
That should see him miss at least the next four games, with his earliest return date likely to be the Merseyside derby at Anfield on February 13.
“Virg was a surprise for us, obviously, a big blow,” Klopp told reporters.
“He didn’t feel a lot [at the time]. I took him off, actually, no risk.
“In the end, the diagnosis was pretty harsh, but we talk about weeks [out] – more than a month – [and not longer].
“I hope it goes quick, but for now he is not available. That’s how it is. We have other centre-halves, as long as that’s the case everything is OK for the team.
“But for Virg, it’s harsh. He played an incredible amount of games over the last years.
“We cannot use him on the pitch at least. Off the pitch, we will do that.”
The manager was then asked whether the injury came as the result of wear and tear for a player who has barely had a break for club or country since his return from an ACL injury.
“Because he played all the games he’s recovering between the games,” he replied.
“He never had an issue with the muscle, never mentioned anything. We did nothing different. It was one sprint too much in that moment.”