'Never had this injury before' - Jurgen Klopp explains why Liverpool are handling uniquely 'tricky' Alexis Mac Allister issue with caution

The World Cup-winning Argentina midfielder was forced off with a knee injury against Sheffield United last week. He subsequently missed the club's Premier League clash against Crystal Palace and has not travelled for the club's Europa League clash against Union Saint-Gilloise on Thursday.

Klopp confirmed on Wednesday that Mac Allister will remain doubtful for their crucial encounter against Manchester United but did not reveal if it was a long-term injury.

Speaking to reporters, the Reds boss said: "I would like to say it’s day to day, but we have to wait until Macca can deal with the pain. It’s a bit more tricky than we thought in the first moment. The studs went through the muscle and to the bone.

"It’s painful for him and we need to make sure there’s no infection. I’ve never had this injury in one of my players before but hopefully, in the next three or four days he makes big steps."

The Premier League leaders are already missing the services of star defender Joel Matip who sustained a season-ending ACL injury during the club's win over Fulham. He has now successfully undergone surgery but is set to miss the remainder of the campaign.

Having already qualified for the Europa League knockout stage, Klopp decided to leave behind several star players like Mohamed Salah, Trent Alexander-Arnold and Virgil van Dijk as the team travelled to Belgium for their final group-stage clash.

On Sunday, they face arch-rivals Manchester United in a crucial Premier League fixture.