Arsenal manager Arsene Wenger has confirmed right-back Mathieu Debuchy suffered a "badly sprained ankle" during the 2-2 draw against Manchester City, while Danny Welbeck had cramps.
The French international defender was force to leave the pitch for Calum Chambers in the 81 minute with an ankle injury, but the boss is still uncertain how long he will be absent.
"Debuchy has a badly sprained ankle, but it doesn't look too good. It will take time to see how long he will be out for," Wenger said in the post-match press conference.
The Gunners were leading the match 2-1 at the time of the French international exit, but Manchester City eventually equalized the game throw a late header by Martin Demichelis.
"It was a game of top quality and we did remarkably well to come back but then we gave a cheap goal away," he said.
"Our goals were done by players who had very good games today."
Referee face with 'lots of fouls'
Meanwhile, Welbeck made a consistent debut for the Gunners after his £16m ($26m, €20m) move from Manchester United on deadline day.
The English international striker played in his favoured position as a number nine, rather than on the flank, and was close to score when striked the post early on the game.
"Welbeck had cramps, but he should be OK. He did well but needs to develop his link play. He looked dangerous."
Manuel Pellegrini claimed after the game referee Mark Clattenburg prevented City for the victory as both Arsenal goals were illegal.
Meanwhile, when questioned about the referee, Wenger said: "There were situations where there was a lot of fouls. It was a difficult game to referee and a very committed one.
"Both managers were frustrated at times and City stopped us a lot on the break in the first half."