"I was going to ask him a question, one of the players was going to put up a rugby bomb - kick the ball up high - and he was going to try and take the catch and answer the question at the same time," he said.
Pryor started out well, giving chase for the high ball.
"Then, he got tackled by one of the players steaming in," Boyce said.
The rest of the Blues players also appeared to have joined in, piling on top of Pryor and Boyce.
"He landed funny but not in a funny way for him, obviously, and the bit of bone in between his collar bone was basically just sticking up - not out of the skin," Boyce said.
Blues player Angus Ta'avao-Matau apologised on Instagram, saying: "When you get told to hit him but not to put him in hospital #SorryBro #SucksToBeyou #JonoAndBen #ItWasntMe."
He shared a photo of Pryor lying on his back on a bed.
The team doctor checked on Pryor after the incident. Filming continued and Pryor was eventually taken to hospital.
"I seem to have broken my clavicle. I didn't even know what a clavicle was until today," Pryor said on the Rock radio show.
"I spoke to the doctor and he said if you were to break it, you've broken it in the perfect location. It's your classic snap halfway across your shoulder."
Footage of the stunt will feature on the Jono and Ben show on Friday at 7.30pm on TV3.
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