How he performs head-to-head against reigning world champion and five-time Green Jersey winner Peter Sagan will go a long way to determining that answer.
Matthews's barnstorming performance at the Tour de France, capped by him becoming the third Australian to win the green jersey category, was no surprise.
It has been inevitable for several years that the 26-year-old Canberra rider would be in the sport's top echelon.
However, for all Matthews' undoubted talent and toughness, Sagan, for now, remains the benchmark.
That is no slight on the Australian, Sagan is superior to nearly everyone. It's simply a fact, that had Sagan stayed in the Tour this year, the BORA-hansgrohe rider probably would have won the Green Jersey for the sixth-straight time.
Instead, race judges controversially disqualified Sagan for the stage-four crash that also took out Dimension Data's Mark Cavendish.
Sagan is second only to German sprint legend Erik Zabel, who won six green jerseys at the Tour. He also has claimed the past two world road titles and his career boasts a whopping 96 pro wins.
Michael Matthews is now the third Australian to win the Tour de France Green Jersey competition after Robbie McEwen (3) and Baden Cooke (1). Born in 1990, he has nothced up two stage wins at the Giro d'Italia and three each at the Tour de France and Vuelta a Espana. He is a world under 23 road champion and finished second to Peter Sagan at the 2015 road world championships. In total he has notched up 29 professional wins. Matthews has ridden for three professional teams in his career, Rabobank (2011-12), Orica-GreenEDGE (2013-16) and Sunweb (2017).
Matthews, well-known as Bling, is also an affable character, earning that nickname for turning up to one of his first bike races showing off some jewellery.
A friend's Dad christened him Bling and it stuck. But he is a lot more than a showy personality.
Three days into his 2015 Tour de France debut, Matthews was hurt in a horrifying mass pileup. Despite bruised ribs, he finished the race.
And this year, as first Sagan and then Marcel Kittel (Quick-Step Floors) moved into the green jersey favourite position, Matthews quietly held his nerve and played the long game.
His Sunweb team rode superbly and he became a contender thanks to his two stage wins. He was only nine points adrift of Kittel when the German abandoned the race in the last week because of a crash.
Matthews has flourished in his first year at Sunweb, which he joined after four years at Australian team Orica-Scott.
And while Matthews and Orica-Scott were good for each other, it was time for a change. The Australian registered team was developing into a general classification team for the Grand Tours and that structure became a difficult fit for the Canberran.
Matthews and Orica-Scott teammate, Australian cycling legend Simon Gerrans, also had their differences, which became obvious at the 2015 road worlds, where he was runner-up to Sagan and Gerrans was also in the top 10.
There were differences of opinion about the Australian team's strategies, though nothing anyone did would have stopped Sagan.
It is no coincidence that Matthews and Sagan keep crossing paths. Orica-Scott rode superbly last year to help the Australian beat the Slovakian for his first Tour de France stage win.
Now Matthews has impressed in Sagan's controversial absence for his first Tour green jersey.
They are similar riders, not pure sprinters, but versatile opportunists who are deadly on a short, steep climb and ideally-suited to cycling's one-day classics.
The sky's the limit for Matthews. And his growing rivalry with Sagan should be epic.
