AJ and Curtis - who himself is a pro dancer on the Irish version of Strictly - were set upon by a group during an evening out on Boxing Day.
The pair suffered bleeding and bruising in the unprovoked attack, with Curtis needing surgery on his knee.
Opening up about the brutal incident this week, AJ has said his brother saved his life - and career.
He told The Sun newspaper: “Curtis risked his own dancing career to save mine as he threw himself in front of the attackers so they couldn’t get to me. He was thinking of both my dancing career with my legs and my TV career with my face.
“He tried to protect me and in doing so saved my life and my legs from danger.
“I soon realised there were no winners in this scenario. I just wanted us both to come out alive. I care more about Curtis than I do about selfies and looking good.”
Brother Curtis added: “It could have been fatal."
Following the attack, Irish TV show Dancing With The Stars revealed at the weekend that Curtis had been forced to withdraw from the show due to his injuries.
“I don’t know what I’ll do if I can’t dance again," Curtis told The Sun. “I just hope that operation can save me. Something can go wrong on the operating table. There’s a chance my dancing career is over.”
A spokesperson for the show said: "Dancing with the Stars pro-dancer Curtis Pritchard was involved in an incident on 26 December 2018. As a result of the injuries sustained, he will not have recovered in time for the launch of the new series, which will air 6 January 2019.
"A replacement for Curtis on the show is currently being arranged and we look forward to welcoming Curtis back when he recovers."