Sean St Ledger has warned his Republic of Ireland team-mates it would be a mistake to believe Sunday night's clash with Croatia represents their best chance of a Group C victory.

The two sides will battle it out with giants Spain and Italy for the right to play in the quarter-finals of Euro 2012, and the Republic are under no illusions about how difficult it could be to get out of the group.

However, they remain confident of doing so and will treat all three opponents in exactly the same way.

Asked if they need to beat the Croatians to progress, St Ledger said: "Everyone keeps saying that, but we played Croatia last year and they are a very good team.

"They have a lot of talent in their squad and that game is going to be the same as the Spain and Italy games. It is going to be a very tough game for us.

"But we are unbeaten in 14 games, we have kept a lot of clean sheets and we can definitely score goals."

The Ireland squad will have been together for a full three weeks by the time they run out at the Municipal Stadium in Poznan on Sunday night.

Their training schedule has been gruelling at times, leading to murmurs of discontent in certain quarters, although both manager Giovanni Trapattoni and assistant Marco Tardelli have insisted they have simply kept the players ticking over since blowing away the cobwebs of a few days' break at the end of the domestic season.

Ireland vs Croatia - Head to Head (as of 8th Jun 2012)
10th Aug 2011 Friendlies Ireland 0 - 0 Croatia  
16th Nov 2004 Friendlies Ireland 1 - 0 Croatia  
15th Aug 2001 Friendlies Ireland 2 - 2 Croatia  

Leicester defender St Ledger said: "For me being in the Championship, we have had a couple of weeks extra. The Premier League boys have only had a week, so it is a big difference.

"It's gone really quickly, to be fair. I think it is because we have changed destinations from Portmarnock and then Italy and Hungary.

"It's been enjoyable. Obviously, these tournaments only come around once every four years, so you just have to enjoy the moment."

St Ledger won his 27th senior cap against Hungary in Budapest on Monday evening and has become a mainstay in Trapattoni's back four alongside the vastly experienced Richard Dunne.

He was only called into the set-up for a friendly against Nigeria in 2009, but has been there largely ever since.

Having started against the Hungarians, he is likely to do so once again when Ireland launch their bid to make the last eight with the manager having confirmed that only injury or unforeseen circumstances would prompt a change to his line-up now.

The 27-year-old said: "The manager has been very good to me since I came in against Nigeria and has put a lot of faith in me, so I have got a lot to thank him for.

"Everyone is really excited for this game against Croatia. It has been 24 years since we have been in this tournament and we have got a very tough group.

"Everybody is looking forward to it and hopefully we can go and get the three points."