Thiago Alcantara did not train with Liverpool's first-team squad on Tuesday ahead of their game against Ajax on Wednesday evening.
Jurgen Klopp's side, who defeated Rangers 7-1 at Ibrox in their last Champions League outing, need to avoid defeat in Amsterdam to reach the knockout stages. If they fail to do that, a point against Group A leaders Napoli at Anfield next Tuesday will also be enough.
Thiago missed Liverpool's 1-0 Premier League defeat to Nottingham Forest at the City Ground on Saturday afternoon with an ear infection and it appears the complaint is still causing him some discomfort. However, there was some positive news with three other injury-stricken starts returning to training.