Robin van Persie's close-range header after 13 minutes proved enough for an eighth straight victory, as the Gunners consolidated their position ahead of the chasing pack.
The Arsenal manager said: "To me it looked very nasty, although I haven't seen it again.
"If it was an accident, it is a very bad accident, because if you see his leg it is unbelievable.
"It is red and bruised from the knee down to the toes.
"We are quite optimistic because Noble is usually a fair player. I don't know if it was an accident or not, but he caught him very well."
Wenger revealed: "I don't think Hleb will play on Tuesday because he cannot walk properly at the moment.
"[Emmanuel] Adebayor had a kick on the thigh, and he looks like he has a good chance to play on Tuesday night."