Napoli forward, Victor Osimhen, was absent at the training session with his teammates on Monday due to his muscle injury.
He suffered a tear in his adductor muscle in March and has missed last two games against AC Milan and Leece.
Popular Italian journalist, Gianluca Di Marzio, disclosed that Osimhen did not take part in squad training.
He was said to have worked individually on the pitch before heading into the gym.
However, Osimhen will go for medical tests on Tuesday (tomorrow) to determine his availability for the UCL game.
Napoli is expected to play against AC Milan in the quarter-final first-leg clash of the UEFA Champions League at San Siro on Wednesday.