Mohamed Salah could return for Liverpool against Genk on Wednesday after returning to first-team training.
The Egypt star has been sidelined with an ankle injury sustained during the 2-1 Premier League win over Leicester City and missed the 1-1 draw with Manchester United on Sunday.
Manager Jurgen Klopp said the forward could not have been risked for the game at Old Trafford as he had not yet resumed team training.
However, Salah was involved in the section of training open to the media at Melwood on Tuesday as Liverpool prepare for their trip to Belgium.
It means the 27-year-old is likely at least to be ready for next Sunday's Premier League clash with Tottenham at Anfield.
Liverpool are a point off the top in Group E after two matches, having lost 2-0 to Napoli before beating Salzburg 4-3 on matchday two.