Arsenal boss Arsene Wenger has fumed at Mark Noble's challenge on Alexander Hleb, branding it as 'very nasty'.
The Gunners came up against a competitive West Ham United side and were forced to battle hard for a 1-0 victory at Upton Park.
On 27 minutes Noble caught Hleb late with a crunching challenge and was yellow carded for the offence.
Wenger conceded that it may have been an accident, but described his player's bruising as 'unbelievable'.
"To me it looked very nasty, although I haven't seen it again," Wenger said.
Red and bruised
"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.
"I don't think Hleb will play on Tuesday because he cannot walk properly at the moment."
Wenger, though, praised his players' spirit and believes his side deserved the three points.
"We had a bit of apprehension because we lost here last season and this was a big test," he added.
"We started with the handbrake on but the goal helped. We didn't make the same mistake we made at Blackburn.
"We continued to play and move forward and try and score the second goal. Unfortunately we didn't get that but we deserved it."