At 41, the Portugal captain was asked before the team's departure for the United States whether he still has enough left to compete at the sport's biggest tournament. His response was as direct as it was pointed.
"Physically? I'm fine - have you not seen my matches?"
The remark captures the mood with which Ronaldo approaches the World Cup being staged across the United States, Mexico and Canada. He arrives not as a fading figure clinging to the stage, but as the leader of a Portugal side that features among the tournament's contenders.
Having completed another demanding season in Saudi Arabia with Al-Nassr, Ronaldo says he feels ready for the toughest challenge of his recent career.
Speaking at the Cidade do Futebol training complex in Oeiras, he was measured on Portugal's prospects but confident in the group around him.
"We don't know if we are contenders or not. That will be seen at the end."
He expressed firm belief in the squad's potential.
"It's a very good generation and I think it's going to bring a lot of joy to the Portuguese people."
Portugal open their campaign against DR Congo on June 17 in Houston, before facing Uzbekistan and Colombia in Group K, a section that on paper should allow Roberto Martínez's side to progress to the knockout rounds. Ronaldo, though, was keen to stress the need to take the tournament step by step.
"The important thing is to start the first match well, then the second, then the third. The path is built by walking it."
Ronaldo's recent fitness assessments with the Portugal squad have reportedly drawn attention within the federation itself. One member of the medical staff who worked with him during his earliest call-ups more than two decades ago was involved in this year's pre-tournament testing, and found some of his physical markers strikingly close to those recorded when he debuted for the senior national team in 2003.
Behind that longevity lies a near-obsessive routine of controlled nutrition, precisely managed rest, personalised training and a discipline that has become his trademark over two decades at the top.
What remains is the toughest assignment of all. Portugal are chasing their first World Cup, and Ronaldo is chasing the one major trophy missing from his collection. He knows the tournament will eventually demand more than physical readiness.
"When things start to get tight, we'll see who the real champions are."
It is a message aimed as much at his rivals as at himself. While the football world keeps asking how much longer he can go on, Ronaldo continues to answer in the only way he knows: playing, scoring, and refusing to accept that the clock has the final word.