Cristiano Ronaldo's age stands as the dominant factor shaping the 72% implied probability against his participation at Euro 2028. At 43, the Portugal captain faces steep physical demands in a high-intensity tournament, compounded by his reduced role in the 2026 World Cup and recent Nations League disputes with coach Jorge Jesus that led to a squad walkout. Portugal has thrived without him in recent matches, relying on younger forwards like Gonçalo Ramos, while Ronaldo's club form at Al-Nassr and history of limited minutes in major tournaments highlight ongoing questions about his starting viability. Although he has signaled openness to continuing if fit, the combination of advancing years, selection tensions, and Portugal's generational shift supports traders' lean toward retirement before the next Euros.