Moment Roy Keane breaks tough guy act for a split second following hilarious interaction with former bitter rival Patrick Vieira on live TV

Roy Keane dropped his tough guy act for a split second after a hilarious encounter with one of his former bitter rivals.

Keane appeared in the studio alongside Sky Sports regulars Micah Richards , Theo Walcott and Paul Merson today ahead of Brighton vs Nottingham Forest .

The star-studded line-up were also joined by Arsenal icon Patrick Vieira via a video link from Chicago, where he was hosting an event for American fans.

Not to miss their opportunity Micah Richards and Theo Walcott were quick to mention Keane and Vieira's old firm rivalry.

Richards began the teasing by asking the Frenchman 'I got your mate in studio here, why you not here. Are you scared? Running scared? What's happening?'

The former Arsenal player was quick to respond jokingly implying 'I can't be in the same room as Roy Keane so I'm better being in Chicago!"

To everybody's surprise a rare chuckle came from the usually stone cold Irishman when the two pundits tried to get a rise out of the two men.

Richards and Walcott however were not satisfied with the response from the two old rivals so continued to poke at the pair.

Richards began the quizzing by asking: 'Who started this?'

Before Walcott added 'he's not kicked me yet but I want to know who kicked more, him or you, Patrick? Who started the famous debate, shall we say?'

Vieira was the first to take Richard's and Walcott's bait and get in on the jokey clash replying 'I think he's the one who started (the rivalry) because he was always scared of me.

'And I think every time he was facing me he was scared of the quality and the challenges that I was giving to him.'

However Keane never one to shy away from an argument, let alone lose one cheekily replied 'Patrick, you know I was never scared of you.

'You are kidding yourself!' he said a big grin on his face.

Fans tuning in loved the reaction between the two who famously clashed in the Highbury tunnel in February 2005.

One fan wrote: 'Micah and Theo digging into one of football's fiercest rivalries! Epic banter!'

A second said: 'sounds like a buddy comedy where both stars are too stubborn to admit they actually just want to be best friends!'

A third added: Richards and Walcott playing referee to the Vieira-Keane drama—this rivalry's more intense than any derby!