Five weeks have passed since Messi was presented as a Paris Saint-Germain player and declared he was in "the ideal place" to win the biggest prize in club football for the fifth time.
In more than a month he has been seen in a PSG jersey for just 24 minutes as a substitute in a Ligue 1 game at Reims.
The 34-year-old had been expected to make his full debut for the Qatar-owned club last weekend but in the end he was rested against Clermont after returning from international duty with Argentina.
However, PSG coach Mauricio Pochettino is expected to finally unleash the six-time Ballon d'Or winner from the start at the Jan Breydel Stadium against Belgian champions Club Brugge in the Group A opener.
If Neymar and Kylian Mbappe start too, it will be the first time the superstar attacking trio will have been on the pitch together for the Parisians.