The Tottenham Hotspur playmaker, who pulls all the strings in Croatia's attacking play, needs to regain his best form after a sluggish couple of months for his club, if they are to emerge successfully from a group that includes holders Spain, Italy and Ireland.
Modric, as skilful as he is slight, has flourished since he moved to White Hart Lane from Croatian champions Dinamo Zagreb in 2008 and is a transfer target of richer rival clubs in the Premier League and Europe.
Tottenham chairman Daniel Levy rebuffed a series of ever higher offers from Chelsea last year and his determination to keep Modric at White Hart Lane boosted manager Harry Redknapp and his team, who had an outstanding first half of the season before their form dipped.
The dynamic Modric, 26, has been equally indispensable to Crotia since making his debut, at 20, in a friendly against Argentina.
He broke into the first team immediately and demonstrated his talent and promise in the 2006 World Cup finals where Croatia narrowly missed claiming a place in the round of 16.
"He is a wonderful player," Redknapp said recently, "and has that gift of creating space out of nothing. He is also a superb example to other players, never a moment's trouble.
"I have been so blessed working with him, and the other Croatians Niko Kranjcar and Vedran Corluka at this club. They are outstanding players and people."
Having won three successive league titles and two cups with Dinamo, Modric shone at Euro 2008 where Croatia reached the quarter-finals only to be eliminated in dramatic fashion.
They took the lead against Turkey in the 119th minute, but conceded an equaliser with the last kick of extra time and then lost the penalty shootout.
Modric was the first of three Croatians who missed.
This morale-crushing defeat did not affect Modric's confidence and he continued playing at a high level for Croatia and new club Tottenham.
His energetic running, vision and ability to deliver defence-splitting passes, as well as shoot from long range with both feet, made him one of the most sought-after players in the world with Manchester United and Chelsea keen to recruit him.
While Modric is essential in Croatia's preferred 4-4-2 formation, several other players may make an impact, led by Modric's Tottenham team-mate Kranjcar, Croatia's top scorer in the qualifiers with four goals.
Although injuries have restricted his appearances this season, Kranjcar, 27, has remained influential as he has been since breaking through in 2004.
Often used in a deep-lying role, Kranjcar has good close control and is effective on either flank, as well as behind a lone striker, thanks to his excellent crossing and dead-ball skills.
Croatia will benefit also from the experience of captain Darijo Srna, 30, who can play right-back or right midfield and is another dead-ball specialst.
Having won 90 caps, Srna is one of Croatia's four most-capped players and has former defender Dario Simic's record of 100 games in his sights.