The Brazil international represented his country during the recent break but was absent when the Reds arrived for the 20:00 GMT kick-off against the Toffees.
His place in the forward line goes to Joshua Zirkzee, who makes his first start of the Premier League campaign.
"It was a knock in the training," revealed the boss in an interview with Sky Sports, prior to the start of the match.
"I don't know how long he is going to stay out. I think it's nothing serious but we cannot risk players.
"We have to show everybody, when you are not 100 per cent, we have a different player to cope with the demands of the game.