Liverpool have suffered a major blow with Roberto Firmino failing to make the matchday squad for their huge Premier League clash against Huddersfield on Friday night.
The Brazilian international reported to the club's training ground at Melwood as normal on Friday morning, but wasn't named in the eighteen man squad for the game at Anfield.
Speaking ahead of the clash against the Terriers, he told Sky Sports (as quoted by the Liverpool Echo): "Actually, yesterday after training he mentioned a little muscle issue.
"We assess it obviously. It's not a big thing but was enough to leave him out today, that's all."
Firmino's injury scare comes just days before the Reds return to Champions League action when they take on Barcelona in the semi-finals on Wednesday at the Camp Nou.
In the Brazilian's absence, forgotten man Daniel Sturridge makes his return to Liverpool's starting line-up against Huddersfield, with Klopp also welcoming back long-term absentee Alex Oxlade-Chamberlain onto the bench after a year out on the side-lines with a knee injury.
After Manchester City's victory away at Old Trafford against Manchester United on Wednesday, the Reds currently find themselves a point behind Pep Guardiola's side, but know that a victory against already relegated Huddersfield will see them return to the top of the table.