The referee had booked Bay Island's James Eadie in just 30 seconds for a reckless challenge on Andy Bevin.
"To be honest, I still don't remember anything," the 19-year-old Rovers player of the season said yesterday, not long after arriving home. "I do remember someone telling me we had won in the hospital but I wasn't sure if I was dreaming or not."
He had viewed video footage highlights that club analyst Tim Motu had played before driving him to Napier.
He had latched on to a through ball but Bay-born keeper William Stockill had blocked his shot. But as John lined up another shot a midfielder, Mario Barcia, had darted in to clear the ball.
"I was falling and I knocked my head into his knee," he said, ruling out any malicious intent on Barcia's part.
A CT scan of the brain cleared him but yesterday John was "a little tired" and was going to sleep after calling his girlfriend, Jodie Williams, in Wales, and his parents.
John thanked player/coach Bill Robertson and English import Ryan Tinsley for keeping the trio posted while he was in hospital.
Gairdner has to clear him to play. The Blues host Palmerston North Marist in a Central League match this Sunday.
"I can't wait to get back on to play the [cup] semifinal."
The venue and opposition for the August 16-17 semifinals will be revealed today.
The other qualifiers are Central United FC, defending champions Cashmere Technical (Christchurch) and Onehunga Sports.
Stockill last night confirmed the chain of events, adding he wasn't involved, although he was 1.5m away.
"I was a good game and a good occasion to be part of.
"We weren't disappointed because we felt it was a big achievement to get as far as we had," the 2013 Rovers Pacific Premiership player said.