Viana replaces Martins in Portugal squad
Viana, 29, is enjoying one of the best spells of his career at Braga, who finished third in the Portuguese Premier league.
The FPF said that Granada midfielder Martins was ruled out of the squad with a muscle injury. Viana has 26 international caps.
Portugal start their Group B campaign against Germany in Ukraine's Lviv on June 9 before facing Denmark and Netherlands in the most difficult pool of all.
The squad started their training camp this week in the old town of Obidos where they will stay until June 2 before leaving for Opalenica, Portugal's base in Poland.