Former Manchester United team-mate Erica Cantona was banned for nine months in 1995 for his kung fu kick on a Crystal Palace fan after he reacted to being targeted having been sent off at Selhurst Park.

The subject of abuse from the crowd was raised this week by England and Portsmouth defender Sol Campbell.

Keane was a fearsome competitor on the pitch but never took his battles outside the playing arena, although he was tempted to.

"I don't think I've ever reacted to a crowd but I think you should be allowed to give a little back," said the ex-United midfielder.

"I wanted to do an Eric Cantona loads of times. I wanted to do it everywhere. Eventually, Eric just thought, 'Enough is enough'.

"In other sports we've seen people go into the crowd and fighting people. I don't sit there shocked. You can see people have had enough."