Liverpool needed late goals from Wataru Endo and Trent Alexander-Arnold to complete a remarkable comeback against Fulham on Sunday afternoon at Anfield, the Reds securing all three points in a memorable win.
However, there will be concern on Merseyside over Matip, the centre-back substituted after 68 minutes due to injury.
Matip went down injured and was swiftly replaced by Ibrahima Konate as the Reds pushed for the win and Klopp has now issued a concerning update on his fitness.
Speaking after the game in his post-match interviews, Klopp said: "Today the big shadow on the game is Joel Matip. A really unlucky situation, but it doesn't look good. I am pretty sure he will be out."
The Reds boss added: "We don’t know how long yet [Matip will be out for], no scan yet. But it won’t be a short one".
Hopefully, Matip's injury isn't as serious as first feared but he will certainly be missing for Wednesday's game with Sheffield United.