Liverpool confirmed the season-ending injury on the eve of their Premier League match against Newcastle United.
Liverpool manager Jurgen Klopp has revealed Calvin Ramsey will miss the remainder of the campaign due to a back problem.
The young full-back joined from Scottish Premiership side Aberdeen last summer but has played just twice for the Reds.
Ramsey hasn’t played a senior match since last year, and Klopp has confirmed how long the 19-year-old will be sidelined for.
“I’ve heard he will miss the rest of season,” the 55-year-old said. “Calvin arrived here and had back problem I’d never heard of before, in a growing process it can happen.
“He had no pain but couldn’t train for a long period.”
Klopp added: “He had no chance – then he came back into a new team – he didn’t train for four months – he is a great talent, a real talent who had the most unlucky start possible.”
The German boss brings his Liverpool side to St James’ Park on Saturday (kick-off 5:30pm) – and will be without an additional four first-team players.
He said: “Same squad as Monday night. Ibou (Konate) not yet, Luis (Diaz) not yet. But that’s it pretty much. Nothing happened on the injury side. Thiago out. Calvin had surgery, not available.”
Thiago is out “for a while” after missing the Merseyside derby on Monday because of a hip issue. Ibou Konate, meanwhile, has missed the last two games with a hamstring issue. Luis Diaz is a long-term absentee.