Mane is of course one of Liverpool's best players and with their front line struggling to finish their chances, it's one of the worst things that could have happened during the global break to Klopp's side, who of course were hammered by Manchester City in their last game against one of the big boys - after Mane was sent off to boot.
With the injury coming so late in the game, around 89 minutes to be exact, it will be a bitter p ill to swallow for Liverpool who faced a dogged time during Mane's absences.
What do Liverpool lose without Mane?
That is according to former Premier League star David Ginola.
Mane has scored three goals in five Premier League appearances this season and has just returned from a three-match suspension.
Liverpool have advanced Philippe Coutinho into the front three to fill in for Mane before, opening up space for Emre Can and James Milner in the midfield, but they have a couple of other options that are intriguing.
Alex Oxlade-Chamberlain can pose the same threat with his incredible speed, though he lacks the finishing and killer instinct of Mane. Without him, that drops to six wins from 13 with 1.6 goals and 1.7 points per game.
He is also set to miss Champions League games against Maribor and league matches against Tottenham, Huddersfield, West Ham and Southampton.