Mikel Arteta's side took the lead through Gabriel Martinelli before Bukayo Saka sealed the victory with a late strike, ensuring Arsenal collected maximum points from their first two group matches.
However, the focus after the game shifted to Gabriel, who was forced off following a collision with goalkeeper David Raya.
Gabriel received treatment on the pitch and appeared to leave the field in discomfort, sparking fears over his fitness. Fortunately, Arteta offered a reassuring update after the match.
"I think he's going to be okay," Arteta said. "He felt something, I think it was a kick, I'm not sure, in the first half, and he was a bit uncomfortable, and towards the second half he was there. He could carry on, but we decided not to take any risks, really, because he's played a lot of games.
"He comes from a long-term injury as well, and we need to look after him."
The Brazilian had previously suffered a hamstring injury in April, which kept him sidelined until the summer, making Arteta's cautious approach understandable.
With Arsenal already missing players such as Saka, Martin Odegaard, William Saliba and Noni Madueke this season, avoiding further injuries is a priority. In the meantime, summer recruit Cristhian Mosquera can provide cover, as he did when stepping in for Saliba last month.
Gabriel is currently valued at seventy-five million euros. Arsenal now turn their attention to Premier League action, hosting West Ham on Saturday.
Nigeria international Samuel Chukwueze has expressed his excitement at rediscovering top form at Fulham, crediting manager Marco Silva for playing a crucial role in his resurgence.
Leeds completed a stunning comeback from 2-0 down to snatch a 3-3 draw against a reeling Liverpool and pile fresh misery on Arne Slot.
Manchester City secured a second successive Premier League victory at home against Sunderland, Chelsea were held scoreless away to Bournemouth while Tottenham managed to beat Brentford.
Aston Villa delivered a major jolt to the Premier League title race as Emiliano Buendía struck deep into stoppage time to seal a 2-1 win over Arsenal on Saturday.
