The defender was forced off in the 69th minute of the Reds’ thrilling 4-3 win over Fulham on Sunday after appearing to twist his knee.
And subsequent scans have revealed a serious injury that will require surgery, likely ruling Matip out for the remainder of the season.
Klopp explained: “It’s an ACL, ruptured. That’s what I unfortunately expected from the first second, everything looked like that. Very unfortunate, that’s it.”
The news represents a double blow for the 32-year-old, whose contract with the club will expire next summer.
That means he most likely made his 201st and final appearance for Liverpool on Sunday, a tally he has clocked up over the course of eight campaigns since joining on a free transfer from Schalke.