Celta Vigo has looked confident in recent matches, especially at home. The team beat Mallorca (2-0) and PAOK in the Europa League, and also put up a fight against Real Madrid (1-2). It's clear that the Galicians are well-organized defensively and dangerous on the counterattack. However, against truly strong opponents, they often struggle to hold on to wins.
Lyon are going through an inconsistent period, but they have a superior squad and experience. The Weavers recently drew with PSG (2-2) and scored three goals against Marseille, despite conceding the same number. Lyon's problem is their defense, but they have attacking talent: Lacazette and Fofana are capable of punishing Celta Vigo's mistakes. The French need to salvage their European campaign.
The visitors have a more experienced squad and will be playing for a result in the return leg. Celta Vigo is good at home, but lacks consistency. Given Lyon's quality of players and their competitive drive, the visitors will at least not lose.