Dias and Bernardo will be certain starters at Euro 2020, but the pair were both involved in the Champions League final on Saturday, with Manchester City losing 1-0 to Chelsea.
Diogo Jota made his return from injury as a late substitute in Liverpool's final match of the Premier League season, and the attacker should be available to start this match.
Head coach Santos also has a decision to make in the final third, as Andre Silva enjoyed an excellent 2020-21 campaign for Eintracht Frankfurt, putting him in a strong position to start the European Championships.
Joao Felix could ultimately get the nod alongside Ronaldo and Jota, though, as two of the powerhouses in international football prepare to lock horns in the Spanish capital.
Portugal possible starting lineup: Lopes; Cancelo, Pepe, Fonte, Mendes; Danilo, Fernandes, Moutinho; Jota, Ronaldo, Felix