Thorn announced his retirement from professional rugby in 2015 after seeing out his contract with the Leicester Tigers in England.
"I didn't actually retire because of my body, I retired because it seemed like I should - I turned 40," Thorn told foxsports.com.au in January.
"If you had have put the number 32 next to my name, as far as age, I would have signed another two-year contract. My body feels good. I've always been open and honest, I just love playing."
The New Zealand-born Thorn first shot to prominence in rugby league, where he played 200 NRL matches and won four premierships with the Brisbane Broncos, represented Queensland 11 times in State of Origin and played eight tests for the Kangaroos.
In rugby, Thorn earned 59 caps for the All Blacks and won the 2011 World Cup.
He earned 111 Super Rugby caps for the Crusaders and Highlanders and joined Rod Kafer in the rare triple feat of winning a World Cup, Super Rugby title and European Cup.