Johan Djourou suffered a knee injury during the 4-4 draw with Newcastle on Saturday.
The Swiss centre back was substituted a few minutes into the second half and headed straight down the players' tunnel.
Djourou scored his first Arsenal goal earlier in the game when he headed in Andrey Arshavin's free kick to make it 2-0 after three minutes.
Stay close to Arsenal.com for news of Djourou's injury.Copyright 2015 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 5 Feb 2011