Defender Joel Matip and midfielder Naby Keita face late fitness tests before Liverpool's Champions League game at Atalanta on Tuesday (20:00 GMT).
The pair trained on Sunday, but midfielder Thiago Alcantara was absent as he recovers from a knee injury.
"We have to wait until the medical department gives us a green, orange or red light," said manager Jurgen Klopp.
Liverpool have won both of their Champions League games this season and are top of Group D.
Meanwhile, Atalanta, who reached the quarter-finals of the 2019-20 competition, have picked up four points from their opening two matches and are second.