The French midfielder picked up a meniscal injury in the Liverpool game and will undergo a minor surgery which will keep him out for four weeks.
"Arsenal midfielder Samir Nasri will today [Wednesday] undergo minor surgery on his knee following a meniscal injury sustained during the match against Liverpool on Sunday," read a club statement. "Nasri, who has been in impressive form, will be out of action for a month."
Nasri was one of the few Gunners who looked bright in that match and his deft touch kept the midfield humming. There was always a chance the moribund attack would get going with him in the midst. Arsenal fans had big expectations of Nasri this season and even coach Laurent Blanc is rebuilding Les Bleus with him in mind.
An injury so early to a key player is not good for team morale. It exposes Arsenal's fragility once again. His absence now puts more pressure to Cesc Fabregas who will have to regain his match fitness and mental composure quickly to put Arsenal back on firm footing.
On the other hand, it gives Tomas Rosicky and Andrei Arshavin an opportunity to step up their game, especially the Russian who looks sluggish and unfocused.
The lucky part is that Arsenal's upcoming fixtures are against relatively weaker teams and Nasri should be back on the pitch to face Chelsea in early October.