L’Equipe reports that William Saliba could face up to a month on the sidelines after twisting his ankle ahead of last weekend’s defeat to Liverpool.
The 24-year-old picked up the problem in the warm-up but opted to start, only to be replaced by Cristhian Mosquera inside five minutes.
Asked afterwards if he was concerned, Mikel Arteta said: “I am because you cannot play a game of that stature. After you tried [to], that means that there is something wrong.”
Saliba has since withdrawn from France’s World Cup qualifiers against Ukraine and Iceland and is also a doubt for October’s return fixture with Iceland and their clash with Azerbaijan.
If the reports are accurate, the defender is likely to have sustained a grade two sprain and will miss as many as five Arsenal fixtures across three competitions: Nottingham Forest at home in the Premier League, a Champions League opener away at Athletic Bilbao, Carabao Cup action at Port Vale, plus league games against Manchester City and Newcastle.
While Arteta is relatively well stocked at centre-back – with Mosquera, Riccardo Calafiori and Piero Hincapie available to partner Gabriel Magalhaes – the loss of another key player so early in the season is a blow. Bukayo Saka (hamstring), Ben White (tan), Kai Havertz (knee) are also sidelined.