Jordan Henderson has been ruled out for up to three weeks with a hamstring injury he sustained against Atletico Madrid.
The Liverpool captain was forced off in the second half of their Champions League last 16 tie first-leg defeat to Atletico.
Henderson, who has been one of Liverpool's best players this season, is set to miss several matches after the club confirmed a lay-off for the England international.
Liverpool manager Jurgen Klopp revealed the news at his press conference ahead of Monday's Premier League game at home to West Ham.
"Hendo, it could have been worse. How we all know, it was a hamstring," Klopp said.
"We heard of different hamstring injuries now around in the Premier League – Harry Kane, for example. It’s not that bad.
"But he will be out, I think, for three weeks or so, which is not cool. But how we see it, we were still lucky. That’s it.
"Hopefully nothing helps happens (to our midfielders). We still have options. There's a chance for all of them. But Hendo wouldn't have played every game between now and end of season."
Liverpool are due to host Atletico in the second leg of their European tie on March 11 and before that have league games West Ham, Watford and Bournemouth.
The Premier League leaders also have an FA Cup fifth-round tie away to Chelsea on March 3.