Liverpool defender Virgil van Dijk is “out for more than a month” with a hamstring problem, says manager Jurgen Klopp.
The Netherlands international was substituted at half-time in Monday’s 3-1 Premier League defeat at Brentford.
Van Dijk, 31, has played in all of Liverpool’s league matches this season.
“It was a surprise for us and a big blow. The diagnosis was pretty harsh,” said Klopp before Saturday’s FA Cup tie with Wolves.
“We talk about weeks, more than a month. It’s a muscle thing – nothing different to say – it was one sprint too much in that moment.
“For Virgil, it is hard for him but he played an incredible amount of games over the last years and we cannot use him on the pitch, only off the pitch, and we will do that.
“He never had an issue with muscles before and it just now happened. That’s how it is. We did nothing different.
Joel Matip, Ibrahima Konate, Joe Gomez and Nathaniel Phillips are Klopp’s other options at centre-back.
In better news for Liverpool, midfielder Jordan Henderson is available once again after missing the Brentford game with concussion.
Klopp added on Henderson: “He did exactly what he was allowed to do yesterday – big parts of team training without heading.
“And from today on I think he’s completely allowed to do everything.”