The mercurial number 10 has been given extra time to recover from football's global showpiece, even though Argentina were knocked out on June 30.
Ernesto Valverde will be without Messi, though, while Spain's Gerard Pique, Jordi Alba and Sergio Busquets also sit out.
That means Barca will have an inexperienced team for the three matches in the States, with the likes of Sergi Samper, Munir and Marlon making the travelling party.
New boys Clement Lenglet and Arthur are also included and will be hoping to make positive first impressions.
Germany international goalkeeper Marc-Andre ter Stegen will sit out an opening clash with Tottenham on Saturday, but will join up with the squad in Dallas for a meeting with Roma on July 31.
Barcelona's International Champions Cup squad in full: Ter Stegen, Cillessen, N. Semedo, Denis Suárez, Paco Alcácer, Digne, S. Roberto, André Gomes, Aleix Vidal, Arthur, Lenglet, Rafinha, Munir, Marlon, Samper, Jokin Ezkieta, Palencia, Cucurella, Mingueza, J. Cuenca, Miranda, Monchu, Collado, Riqui Puig, Abel Ruiz, C. Pérez, Chumi and Ballou.