Onana joined Manchester United from Inter Milan in the summer of 2023 but has not been able to secure a regular spot in the team.
Amorim's decision to choose Altay Bayindir over Onana for the Arsenal match has sparked speculation about Onana's future at Old Trafford.
Amorim explained his decision by saying that he chose the best players for the game, and that Onana would have a chance to play in the next match.
Amorim also clarified that Onana was not injured, but rather, he wanted to give other players a chance to play after their good performance in the pre-season.