Spurs midfielder under no illusions as to the weight of the task ahead of his side's Euro 2012 Group C campaign, sharing the bill with Italy and Spain
The Tottenham playmaker has declared himself fully fit for the tournament after undergoing a special recovery programme in order to refresh and revitalise himself after a long season.
Slaven Bilic's side have been drawn alongside the Irish, as well as defending champions Spain and Italy in their group and speaking to Spurs TV, Modric made it clear how crucial a winning start to the group would be.
"The first game is always difficult. There is a lot of tension, everyone wants to win and play well. Whoever wins that game has a massive chance to go through. I hope we can win it but Ireland will be tough.”
The 26-year-old has won 54 caps for his country and will be key to Croatian chances in Poland and Ukraine; more so after the withdrawal of talismanic striker Ivica Olic due to injury.
Looking ahead to Sunday’s game, Modric is aware of the challenges that he and his team-mates will face after playing Trapattoni’s side in a friendly less than a year ago.
"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."