Ronaldo first played in the European championship in 2004 before winning the competition in 2016, and will likely make an appearance at some stage during his record-extending sixth tournament later this month.

The 39-year-old is the leading scorer in men's international football, netting 128 goals in 204 official matches, with 14 of those coming in the European championships.

Ronaldo is entering what could potentially be the final major tournament of his remarkable career, and Martinez is hoping to draw on all the experience of the former Manchetsre United, Real Madrid and Juventus star ahead of that opener.

"Cristiano had very consistent performances at his club. There is no doubt that he is an incredible scorer," Martinez said.

"He is in his sixth European championship, and he is the only player who has played in five European championships. So, we are talking about achieving a unique feat in the world of soccer and his experience is important for us.

"We have 23 players. We create competitiveness and the game makes decisions. But Cristiano is prepared to help the team and give everything he can give. And there is no other player in the world of soccer who can bring what Cristiano can to the dressing room."

Portugal lost its final warm-up game against Croatia on Sunday (AEST), a 2-1 defeat its first against the eastern European side.

Martinez's team begins its UEFA Euro 2024 campaign in Group F against Czech Republic on 19 June.