Coutinho has suffered a ‘slight abductor strain’ in training this week and will miss the Terriers’ visit to Anfield.
It comes as a significant blow to Jurgen Klopp, who remains without long-term attacking absentees Sadio Mane and Adam Lallana.
Klopp has, however, been boosted by the return to training of Georginio Wijnaldum after a knee complaint.
Alex Oxlade-Chamberlain could come into contention for a starting place as the Reds look to get back on track after their 4-1 defeat to Spurs at Wembley.
In comparison, David Wagner's side travel to Merseyside buoyed by the return of Collin Quaner from a month-long absence and Elias Kachunga's recovery from a back problem.