They meet Sweden in their first match in Group E in Paris at 5pm.
Manger Martin O'Neill is hopeful that Jonathan Walters, who has been struggling with an Achilles problem, will be available for the clash.
Midfielder Stephen Quinn says the squad will have a relaxing day ahead of kick-off.
Elsewhere in Group E, Belgium face 2012 runners-up Italy in Lyon at 8pm.
Belgium captain Eden Hazard limped out of training on Friday after being trodden on but is expected to be fit.
Italy may start with Antonio Candreva and Stephan El Shaarawy as attacking wing-backs.
Italy are unbeaten in their three games with Belgium at major tournaments.
First up, two-time defending champions Spain begin their campaign against Czech Republic in Toulouse at 2pm.
David de Gea is in contention to start their Group D opener after receiving the backing of manager Vicente Del Bosque.
The Manchester United goalkeeper has been forced to deny allegations about his private life after reports in Spain linked him to a sex scandal.
Spain are unbeaten in their last 12 games at the European Championships.
