Martin O'Neill says Roy Keane's 'volatility' will do no harm

New Republic of Ireland manager Martin O'Neill believes his assistant Roy Keane will become an asset to the national team, saying the ex-Manchester United midfielder's "volatility" can be a good thing.

"I think he will be brilliant for the Republic of Ireland and I will want him basically the way he is," said O'Neill.

"I have found him very, very engaging and his thirst for knowledge amazing.

"A little bit of volatility will do no-one any harm. And Roy as well."

Speaking at his official unveiling as Republic boss in Dublin, O'Neill said Keane had taken "about four and a half seconds" to make up his mind about becoming his assistant.

Keane won 67 international caps in his playing career, but caused controversy as captain of his country when he quit the Republic squad before the 2002 World Cup after falling out with then manager Mick McCarthy.

After being introduced as the new Republic boss by Football Association of Ireland chief executive John Delaney, O'Neill did refer to Keane's falling out with Sir Alex Ferguson which led to the Cork man's exit from Manchester United in 2005.

"One of the greatest managers in the game finally decided that Roy was no longer wanted because he felt he (Ferguson) was going to be overshadowed," said O'Neill.

"But all told I think it will be great. I think it will be great for me but, more importantly, I think it will be brilliant for the people of Ireland."

O'Neill spoke of his huge admiration for Keane the player but said his respect for the 42-year-old had increased as a result of their recent television work together for ITV.

"I see him at football matches when there is no need for him to be there," said O'Neill, who revealed Keane was attending Saturday's Premier League game between Aston Villa and Cardiff City.

"He loves football. When I did mention the possibility of him working with me here, it took him about four and half seconds (to say yes). He was absolutely delighted."

O'Neill added that he didn't "intend to change Roy too much".

"I will maybe make the occasional adjustment if that's possible," added a smiling O'Neill.

O'Neill and Keane will meet with the Republic squad for the first time on Monday evening ahead of Friday's friendly against Latvia in Dublin.