When Portuguese footballing legend Cristiano Ronaldo is unveiled by Saudi Arabian club Al Nassr on Tuesday in Riyadh, it will mark a seismic shift in Asian football although raising questions from all corners of the globe as to whether this is the beginning of the end for the five-time Ballon d'Or winner.

To fully justify both ends, it is prudent to begin by examining the potential advantages of Cristiano Ronaldo's move to Asia, and how it could further invigorate the growth of football in the region.

Al Nassr sent shockwaves through the global sports world on Friday when they took to social media to announce the signing of one of the world’s most celebrated athletes.

In less than a day, the post had been seen by an astonishing 20 million people, generating an impressive 2.5 million more followers for the club.

There was a similar surge on Instagram, where the Portuguese star has more than 520 million followers, the most in the world. There, the announcement received more than 30 million likes.

"This agreement is more than writing a new historical chapter," Al Nassr President Musalli Al Muammar said.

Renowned for his extraordinary on-field feats, Ronaldo has won five European Champions Leagues with Real Madrid and Manchester United.

However, his second stint at the latter, a period of being a bench regular without any silverware, was far from illustrious, with his contract being prematurely terminated due to a controversial interview with Piers Morgan.

Al Nassr's new coach Rudy Garcia who has coached Lyon and Roma said, "The signing of a player the size of Cristiano Ronaldo is extraordinary, and contributes to the development of Saudi football."

He added, "We are happy with his arrival. The first goal is to work so he can adapt to our team, to enjoy playing for Al Nassr, and to entertain the fans."

Al Nassr, a nine-time Saudi Arabian champion, is already going well near the halfway stage of the Saudi Professional League. It moved into the lead on Saturday after winning at Al Khaleej 1-0 thanks to Cameroonian striker Vincent Aboubakar.

Other names at the club include Colombia goalkeeper David Ospina, formerly of Arsenal and Napoli, and 2018 South American player of the year Pity Martinez. Brazilian Anderson Talisca leads the goal-scoring chart.

Despite such talent, the league does not have a wide audience internationally. That may change thanks to Ronaldo, who will reportedly earn up to $200 million a year.

"The whole world knows Ronaldo very well and his achievements as a player speak for themselves," former Saudi Arabia international Hamad al-Montashari said. "He is an exceptional player and could score a hat trick in every game."

Had the soon-to-be 38-year-old superstar left Europe five years ago, then China would have been a realistic destination. The massive wave of spending there in the previous decade has ended, however. With real estate companies financing much of the transfer activity, the massive slowdown in China’s property market has seen the majority of clubs struggling to make ends meet.

On the other hand, we also have to understand that no matter how popular among his loyal fans CR7 might be, he is way past his prime and unfortunately it is not doing him any good.

Unwanted by Europe's elite clubs, his steep decline has been laid bare by the move to Al Nassr that signals the end of his reign as one of football's most feared strikers.

The riches and fanfare that await the 37-year-old in Saudi Arabia are at odds with his reduced status as a fallen star trading on past heroics.

For Ronaldo, to be forced to play out what will surely be the final chapter of his glittering career in the football backwater of Saudi Arabia is a damning indictment of his lackluster form over the last 18 months.

As his relationship with Manchester United soured, Ronaldo was linked to a string of Champions League contenders including Chelsea, Bayern Munich and Napoli.

A return to his first club Sporting Lisbon was also rumored, while there was talk of a move to the MLS to join Inter Miami, part-owned by former United teammate David Beckham.

But none of those deals came to fruition and when United decided his diminishing contribution, coupled with his public displays of dissent, made him a pricy luxury they no longer needed, it was instructive to note the absence of a rush to sign the aging icon.

Coming at the same time as his acrimonious United exit, Ronaldo's failed quest to finally win the World Cup underlined his descent into the ranks of football's mere mortals.

Tears in Qatar

In a move that would have been unthinkable just a few years ago, Ronaldo was left out of the starting line-up for Portugal's last 16 thrashing of Switzerland.

And when Portugal suffered a shock 1-0 defeat against Morocco in the quarter-finals, Ronaldo started on the bench, made little impact after his eventual introduction and was last seen trudging down the tunnel in tears after the final whistle.

There was a sting in the World Cup tale for Ronaldo as it was his old sparring partner Lionel Messi who got his hands on the trophy for the first time instead.

The sight of Messi lifting the World Cup after Argentina's final victory over France in Qatar will have pained Ronaldo given their long-standing rivalry.

Few would question Ronaldo's right to be regarded as one of the all-time greats after winning five Champions League crowns and a combined seven domestic league titles with United, Juventus and Real Madrid.

He is also the record goal-scorer in the Champions League and with the Portuguese national team, who won the 2016 European Championship – Ronaldo lasted less than half an hour before going off injured in the final against France.

But Messi's triumph with Argentina vaulted him into the ranks of football's immortals alongside Pele and Diego Maradona, a rarefied air that Ronaldo will never sample without a World Cup victory on his CV.

Ronaldo's decision to accept the lucrative deal offered in the Middle East rather than play on for a lesser European team made it clear he knows his diminished place in the football hierarchy.

Kylian Mbappe, Erling Haaland and Mohamed Salah are the new global stars stepping into Ronaldo's boots.

However, for the millions who have been captivated by Ronaldo over the last two decades, this version of the superstar is very far from his best.