December 2, 2019 could yet prove a crucial date in the eternal debate over Lionel Messi and Cristiano Ronaldo's credentials as the greatest footballer of all time. 

The duo are tied on five Ballon d'Ors a piece, a stalemate which could end next month if one of them overcomes Virgil van Dijk, the other favourite. 

There is very little between the Barcelona and Juventus forwards when it comes to personal records.

Ronaldo has scored 702 goals to Messi's 680, though he's also played 146 more games. 

The Argentine has 57 more assists (272 to 220), which perhaps explains accusations of selfishness that have followed his Portuguese counterpart throughout his playing days. 

One way of deciding between the two is by judging their international careers. It's there that Ronaldo comes out on top with a European Championship winners' medal from 2016.

However, neither of them has won a World Cup. For some, that will always hold them back in any conversation about the greatest ever to play the game. 

Chelsea's Willian has now weighed in with his opinion, and his pick for the best of all time is indeed one of his compatriots who has won the most coveted trophy of all: Ronaldinho. 

The legendary Brazilian enjoyed his best years at Barcelona between 2003-2008 and won two La Liga titles and a Champions League. 

With the Seleçao, he also lifted the World Cup in 2002, three years after claiming the Copa America in 1999. 

Yet it was his style of play that means he stands out for Willian. He's quoted by the Mirror: 

"Ronaldinho was the best of all time. Better than Messi and Cristiano. 

"They score goals, but what Ronnie did was incredible. He was amazing on the field and also scored.

"As a fan of his, I have to say that he left [Barcelona] too soon. 

"If he had kept up the level a couple of years, he would have won many more Ballon d'Or's."

While Messi and Ronaldo are both a joy to watch, there was something unique about Ronaldinho's style of play, his fluidity, his elasticos. The attacking midfielder could dazzle with his effortless skills. 

It will certainly be an interesting conversation when Willian lines up against Messi, however, as Brazil take on Argentina this Friday in Saudi Arabia.