Modrić suffered a facial fracture a few weeks ago and has not played since, and sat on the bench for Milan's 2-1 win over Genoa at the weekend.
National team captain Zlatko Dalić expects the 40-year-old midfielder to be ready to play. Modrić is facing his fifth World Cup final.
Another veteran is Ivan Perisić, who has scored in the last three World Cup tournaments.
Other familiar names in the squad are Manchester City's Josko Gvardiol and Matteo Kovacic, and Inter's Luka Sucic.
Croatia plays in the same group as England, Ghana and Panama.
Facts: Croatia's World Cup squad
The squad:
Goalkeepers: Dominik Livaković, Dominik Kotarski, Ivor Pandur.
Defenders: Josko Gvardiol, Duje Ćaleta-Car, Josip Sutalo, Josip Stanisić, Marin Pongracić, Martin Erlić, Luka Vusković.
Midfielders: Luka Modric, Mateo Kovacic, Mario Pasalic, Nikola Vlasic, Luka Sucic, Martin Baturina, Kristijan Jakic, Petar Sucic, Nikola Moro, Toni Fruk.
Forwards: Ivan Perisić, Andrej Kramarić, Ante Budimir, Marco Pasalić, Petar Musa, Igor Matanović.
Reserves: Lovro Majer, Franjo Ivanovic, Dion Drena Beljo, Ivan Smolcic, Karlo Letica, Adrian Segecic, Luka Stojkovic.
