Mane limped off during the Reds’ 3-1 win at home to Everton last weekend, and was initially hoped to be back in action imminently.
However it quickly became clear following scans that the 24-year-old’s condition was more severe, with the club waiting on results to determine whether surgery was necessary.
And speaking ahead of Liverpool’s clash with Stoke City on Friday, the German confirmed Mane’s season is over.
“Sadio now we’re pretty sure will need surgery. We’re not 100 percent when it will happen, but yes, it’s clear: season over,” he told reporters at Melwood.
“That’s what I half-expected when I saw the video after the game, I thought it was lucky nothing more happened.
“Now we’re close to the end of the season and it means it will be pretty much impossible he’ll play again this season.
“Then we’ll have a long break and be ready for the next season, that’s the only good news.”