"They are slightly different players and different, what we call somatotypes, which is their body physique," he said. "But clearly those guys playing at the highest level for so long have understood what they need to do to sustain it, whether that is working in the gym, watching what they eat, sleep.
"With all these guys, if you look at any industry, the best of the best will either keep recreating themselves, but will keep continuing to work at being the best of the best."
Neither Messi nor Ronaldo will be defined by the World Cup even if it continues to elude them. Times have changed and club soccer has largely overtaken the international game in terms of profile and popularity because of the success of the Champions League and the Premier League in particular.
Fans around the world have been able to witness the brilliance of Messi and Ronaldo on a twice-weekly basis, which was never the case with Pele or Maradona.
Their respective feats for Barcelona and Real Madrid, especially, created a rivalry unlike any seen in the sport, with the Ballon d'Or almost becoming a personal duel for more than a decade, while their scoring tallies were driven to ever-increasing heights.
Such have been their achievements at the highest levels of the club game that any argument suggesting they need to prove themselves in international competition have been rendered redundant. Not least because both have ended their barren runs with their national teams with Ronaldo inspiring Portugal to victory at the 2016 European Championship and Messi winning the Copa America with Argentina last year.
But the World Cup is the final frontier - and perhaps an opportunity for one of these remarkable players to write one glorious final chapter.