Irish legend Roy Keane has urged the Boys in Green to make the perfect start to the European Championships and beat Croatia on Sunday.

Keane believes Ireland’s opening group game in Poznan will present their best chance of a win before the tests to come against Spain and Italy.

The former Irish captain told reporters that this Irish team is, he believes, capable of ‘one big result’ at Euro 2012.

“It will be tough for Ireland, but they will have a good go as all Irish teams do,” said Keane.

“The biggest game for Ireland is the game against Croatia. They have to get something because if you go to the second game against Spain without a point, it will be very, very difficult.”

Keane added: “But what you might find with Ireland, which they have done in all major tournaments in which they have qualified, is that they get that one big result - but they have to get a result against Croatia.”

Working at the Championships for the ITV station in England, Keane is backing Ireland to cause some sort of upset along the way.

The former Manchester United star continued: “Ireland always bring something different to a tournament - they have spirit, the supporters, that gives you a chance.

“Technically they will be well behind the three teams they are playing, and they will have very little possession, but recently, you look at Chelsea, in football matches, possession has not been the biggest priority - it is about keeping solid.

“They are not bad at set-pieces, and that may be their only hope.”

Sunderland winger James McClean, who will start Sunday’s opener against Croatia on the bench at best, has also been backed to make an impact by Keane.

He said: “James McClean is a good player, and it is good for Ireland, you need young players coming through.

“Obviously he has had some difficulty because he has been criticised for not playing for Northern Ireland, but he has made his decision.

“He has enjoyed playing under Martin O’Neill, has had a break there and been a good asset.

“He might be a surprise package in that the other teams won’t have seen too much of him, because he is a big strong boy, and can get you goals.

“If he can bring his club form to the team he can get in that starting XI.”