Gabriel Magalhaes was forced to leave the pitch with an injury during Arsenal's emphatic 5-1 Champions League victory over Sporting, Mikel Arteta has confirmed.
The Brazilian defender, who netted the third goal for the Gunners, was substituted for Jakub Kiwior due to discomfort.
Arteta shared post-match: "We had to make the change because he was feeling some discomfort. I was about to make the change for Raz [Raheem Sterling], poor thing, I couldn't make the sub. We had to get him out."
The incident slightly marred what was otherwise a spectacular evening for Arsenal, marking their largest Champions League win in over two decades.
Without manager Ruben Amorim, Sporting struggled from the outset as Gabriel Martinelli swiftly opened the scoring, followed by Kai Havertz's goal. Gabriel then delivered a powerful header before half-time.
Sporting attempted a comeback after the interval, applying pressure on Arsenal, but goalkeeper David Raya and a series of outstanding saves kept their efforts at bay.
Bukayo Saka later secured the victory with a penalty, earned by Martin Odegaard, and Leandro Trossard topped off the night with a fifth goal.
Concerns arose when Gabriel sustained his injury, requiring assistance from the referee and team-mate William Saliba.
Arteta had been gearing up to bring Sterling into the game, but was forced to rethink his strategy when Gabriel needed to come off. The Gunners boss will be hoping for a swift recovery in time for their Saturday evening clash with West Ham.
Arsenal are heading to the London Stadium with the aim of securing consecutive Premier League victories, following their impressive 3-0 triumph over Nottingham Forest last weekend.