Luka Modric claims Croatia's opening Euro 2012 game against Republic of Ireland could prove to be the most decisive game in the group.
Slaven Bilic's side also face Italy and reigning world and European champions Spain in a tough-looking Group C.
But the Tottenham playmaker believes it is crucial the Croatians make a winning start when they come up against Giovanni Trapattoni's side at the Municipal Stadium in Poznan on Sunday evening.
"The first game is always difficult. There is a lot of tension, everyone wants to win and play well," Modric told Spurs TV Online before departing for the tournament.
"Whoever wins that game has a massive chance to go through. I hope we can win it. Ireland will be tough.
"We played against them last August and it was 0-0 and you could see at that time how hard it would be to beat them and break them down. They are very experienced, with an experienced coach.
"They have some very good players. It will be hard. Ireland are a nation, they like to fight, they have a strong, positive mentality. That's why it will be hard for us but we have to win the game if we want to have a chance of going through."