Ronaldo, who will be 41 when the competition begins, is currently playing for Al Nassr in Saudi Arabia and remains a regular in the Portugal squad.
If selected, he would become the first player to appear at six World Cups. Portugal head coach Roberto Martinez has continued to back Ronaldo's influence and professionalism, while his form and fitness will remain key factors in any final decision.
Messi will be 39 during the tournament and has previously suggested that the 2022 World Cup in Qatar, where he led Argentina to the title, was likely his last appearance on the global stage. However, he has not ruled out returning, stating that his involvement would depend on his physical condition and motivation.
The Inter Miami forward remains active in Major League Soccer, and Argentina coach Lionel Scaloni has said there will always be space for Messi should he wish to continue.
According to sports betting odds, defending champions Argentina are currently among the leading contenders for the 2026 title, which could add further incentive for Messi to remain involved if the team maintains its form through qualification.
Qualification campaigns and squad planning over the next year will play a decisive role in determining whether two of football's most decorated players return for one final tournament.
Should Ronaldo and Messi both take part, the 2026 World Cup would likely mark their final appearances on the global stage, as players such as Kylian Mbappe, Vinicius Junior and Jude Bellingham continue to shape football's next era.