Arsenal qualified for the knockout stages of the Europa League with a goalless draw at home to 10-man Sporting Lisbon in a game overshadowed by a potentially serious ankle injury to England forward Danny Welbeck.
The attacker required an oxygen mask as he was treated on the pitch, with a leg brace also in place after landing awkwardly on his ankle while trying to attack a header from his Swiss colleagues' centre.
The Gunners are yet to confirm the exact nature of the issue, although it appears the forward is set to miss several months.
One even went as far to say that he had been their worst ever signing.
Rob Holding: "I didn't see it because obviously I'm at the other end of the pitch so I didn't see exactly what he'd done".
If Sporting CP is able to snap Arsenal's unbeaten streak, it would pull level atop the group on points, making for a more dramatic run-in over the final two matches.
"Danny is a tough lad, so if he's on the floor, I know it's something serious".
Welbeck, who was injured when he jumped for a header and landed badly on his right ankle, remains in hospital and will continue to be assessed. "He can come back strong". "His injury was with the mentality of the players". Welbeck was available for sale in the summer, Arsenal had not offered him a new contract and likely are not planning to do so.
"The best for him is now to think for the person", Emery said. After the match, Emery confirmed that his back-up striker had suffered a "big" injury and that he had immediately been taken to hospital.