If he were to enter the game's top level, Rioux would be above any of its current players in terms of height.
The NBA lists 21-year-old French sensation Victor Wembanyama as its tallest, with the San Antonio Spurs star measuring 7ft 4in (2.24m).
Zach Edey, of the Memphis Grizzlies, is next with the 23-year-old standing 7ft 3in (2.21m).
Three other players are 7ft 2in (2.18m), according to the NBA's official website.
They are 23-year-old Donovan Clingan, of the Portland Trail Blazers, 24-year-old Walker Kessler of the Utah Jazz, and Kristaps Porzingis of the Atlanta Hawks.
The NBA's tallest ever players are listed as Manute Bol and Gheorghe Muresan, who were both 7ft 7in (2.31m).
Bol played between 1985 and 1997, while Muresan, who was nicknamed the Giant, was on court from 1991 to 2001.