Is Ronaldo's superpower declining as Al Nassr reveal he suffers from fatigue?

Across the sporting world, players have repeatedly tried to bend time to their will.

Tom Brady won a Super Bowl six months short of his 44th birthday, while James Anderson has continued to take wickets with metronomic accuracy long after turning 40.

Lionel Messi was relatively wet behind the ears as he inspired Argentina to World Cup glory at the age of 35.

Ultimately, Father Time remains undefeated even against the very best, no matter how strict their diets and how obsessive their fitness routines.

Cristiano Ronaldo was offered a brutal insight into the life of an ageing athlete this week, when he missed Al-Nassr's Asian Champions League tie against Al-Duhail on Tuesday because of fatigue.

Al-Nassr head coach Luis Castro stressed that the Portuguese needed to recuperate from the exertions of recent matches.

'Cristiano Ronaldo will not participate in the Al-Duhail match because he is tired due to his many participations,' he said.

'I know that there are those who want to see him, but he needs to rest. He is not ready, but we have many stars.

'I did not decide to exclude the legend Cristiano Ronaldo, but his capabilities decided that.

'Because 48 hours ago he played a match, and before that he played 120 minutes.'

In normal circumstances, resting a 38-year-old to allow him to recover from a gruelling schedule would hardly be newsworthy.

Except that Ronaldo isn't a normal 38-year-old athlete.

Like Brady, the Portuguese is notoriously fastidious about his diet and wears his obsession with his health and fitness routines proudly on his sleeve.

Ronaldo supplements squad training sessions with a personal workout plan.

His five weekly trips to the gym include 25-30 minutes of cardio, high-intensity sprinting and targeted weights to