Fabinho was pictured leaving Anfield wearing a protective boot after suffering an injury during Liverpool's Champions League match against Napoli on Wednesday night.
The Brazil international limped off the pitch after 18 minutes following a clash with Mexican forward Hirving Lozano.
Gini Wijnaldum came on to replace his team-mate in the Group E showdown which ended in a 1-1 stalemate.
Fabinho was subsequently pictured leaving the ground wearing a protective boot over his left ankle.
Former Barcelona star Deco was in attendance at the home of the European champions and posted a picture to social media which showed the defensive midfielder in high spirits despite suffering the knock to his ankle.
The 42-year-old, who ended his illustrious career at Fabinho's first club Fluminense, wrote: "Always a pleasure to see you brother.
"Soon will be recovered."
Following the match Jurgen Klopp issued an injury update on the former Monaco man.
The boss said: "Fabinho has pain, so that's not good.
"He couldn't continue, and he is a hard one.
"I don't want to say what I expect because I hope at the moment it's not that serious.
"We will know more maybe tomorrow or maybe the day after tomorrow. That's it."
Fabinho was already set to miss this weekend's Premier League meeting with Brighton at Anfield after picking up a one-match ban following the yellow card he received in Liverpool's 2-1 win over Crystal Palace.