The Premier League leaders needed a late Kai Havertz penalty to secure the draw against Leverkusen in their round of 16 first leg in Germany.
Advertisement
Advertisement
Trossard, 31, was sidelined for the game having failed to shake off a muscle injury, despite returning to training on Tuesday.
Speaking to reporters after the game, Arteta provided an update on the Belgian’s fitness, saying: "Yes he trained yesterday but he wasn't comfortable to play.
"He said he was still feeling something. You need at this level to play 100% and he wasn't."