William Saliba is an unexpected absentee from the Arsenal squad to face Chelsea in Sunday's Premier League London derby, and the Gunners have revealed why the Frenchman is missing from the team.
The France international came through the 3-1 Champions League win over Bayern Munich unscathed and was expected to retain his spot in the first XI for the tantalising clash with the Club World Cup champions in the capital.
However, Saliba was an unforeseen omission from the matchday squad at Stamford Bridge, with Arsenal revealing that he had suffered a knock in training during the week.
The France international joins regular centre-back partner Gabriel Magalhaes on the sidelines for the London derby, as the Brazil international watches on with the thigh injury he sustained during the recent international break.
Arsenal's defensive strength in depth means that they can still put out a strong central pairing of Cristhian Mosquera and Piero Hincapie, but Saliba and Gabriel's blows will represent a brand-new challenge for the Gunners boss.
Chelsea vs. Arsenal: Mikel Arteta seeks 2024-25 repeat amid Saliba, Gabriel injury blows
Sunday's clash with Chelsea will represent just the second Premier League game where Arsenal have been without both Gabriel and Saliba in the starting lineup since the latter made his debut in the competition in the 2022-23 campaign.
The only previous instance came last season, where Kieran Tierney and Jakub Kiwior paired up in the backline against already-relegated Southampton on the final day of the term, helping the Gunners to a 2-1 win.
Arsenal have also navigated EFL Cup wins against Bolton Wanderers, Brighton & Hove Albion and Crystal Palace without Saliba and Gabriel, but they have never faced a doomed team in the Premier League without either defensive rock.
Saliba was seen arriving with the squad at Stamford Bridge, but only when the lineups were released did it emerge that there was a problem with the France international, who will miss just a second game this season due to injury.
Saliba was also absent from September's 3-0 victory over Nottingham Forest as a result of an ankle problem, and he joins Gabriel, Kai Havertz and Leandro Trossard on Arsenal's injury list for this weekend.
More to follow.