Liverpool midfielder Fabinho suffered an ankle ligament injury in Wednesday's Champions League draw with Napoli and will be out of action until the New Year, the Premier League club said on Friday.
Fabinho, ranked the No. 6 central midfielder in ESPN FC 100, was injured in a collision with Napoli winger Hirving Lozano and the midfielder limped down the tunnel in the 19th minute as Klopp took off the Brazilian and replaced him with Georginio Wijnaldum.
"Further assessment on the injury has discovered Fabinho will be out of action until the New Year," the club said in a statement.
"The Brazilian will begin a rehabilitation programme with the Reds' medical team at Melwood as he works his way back to full fitness."
Liverpool boss Jurgen Klopp has expressed his concern about the news but he is confident the club can find solutions to cope without the Brazil international.
"It is absolutely bad news, nothing good to say about that," he told a news conference "The timeframe we are not sure 100% but it looks pretty sure he won't be involved in the Christmas fixtures. It takes a while.
"Hendo has played in that position, Gini has, Lallana has. We can change system and do different things. Losing a player with quality of Fabinho is massive but we are not the only team with injuries."
The injury comes at a crucial time for league leaders Liverpool who are set to play eight fixtures in all competitions between now and the end of December, including a trip to Qatar for the Club World Cup.
The defending European champions are also yet to seal progress to the Champions League knockout stages, with one final away game at Salzburg next month.
Klopp also expressed his frustration after match commander David Duckenfield was found not guilty of gross negligence manslaughter at the 1989 Hillsborough disaster.
"The most important thing is our thoughts and love are with the families," he added. "We are there for them.
"It's a big disappointment, frustration, sadness of course, that this looks like the final verdict."