Gallas was caught on camera kicking out at his opponent during United's 4-0 FA Cup victory on Saturday.

As referee Alan Wiley failed to see what happened, Ferguson in his post-match briefing called for the official to look at it again and issue a retrospective red card.

However the Football Association have decided against taking action and while Ferguson is prepared to let the matter rest, he claimed "three or four red cards" could have been dished out to Arsenal.

One Gunners player was dismissed - Emmanuel Eboue for a clumsy challenge on Patrice Evra in the 49th minute.

On Gallas, Ferguson said: "It is hard to assess to be honest.

"I think a lot of clubs are disappointed they have players who suffered from a retrospective view of incidents.

"Maybe for Alan Wiley, it was a tough game in the second half for him.

"He probably had enough, was quite happy to put a marker under it and get a rest. There could have been three or four red cards for Arsenal.

"The important thing is everyone has been made aware of the incident. That's the thing we don't need to answer. We are happy to leave it now."