He is ranked 23rd in the Chosen 25 for the class of 2020.
Mannion (6-3) the azcentral sports Player of the Year, had been working towards reclassifying for a year.
Pinnacle coach Charlie Wilde told azcentral sports in May that Mannion that it had been discussed since his freshman year.
He led Pinnacle to its first 6A state basketball championship last season.
Pace Mannion, Nico’s dad, told azcentral sports in May that this would be his last club circuit. He is currently playing in a tournament in California for West Coast Elite. Pace said then his son was taking online courses in order to graduate in 2019.
Mannion announced his top 10 college choices back on June 4, with the Arizona Wildcats among them.