He is the younger brother of fellow Wests player Ward Prentice.
In 1915 Clarrie, and his brother Archie, joined the Western Suburbs Rugby League Club.
His international rugby league debut against New Zealand in Wellington on 23 August 1919, alongside Claud O'Donnell saw them become Australia's 20th and 21st dual code rugby internationals.
It wasn't until 18 years later that Doug McLean jnr would become the next Australian dual representative.
Prentice was selected on the 1921–22 Kangaroo tour of Great Britain.