Parker is training three times a day, starting with a 6am run. It is a regime which has come as a bit of a shock, said Barry, but he is coping well with it. He has lost five kilograms and could easily shed an extra four to make light heavyweight.
He wasn't quite as easygoing about the recent South Island earthquakes, however. Staying at Barry's home in the suburb of Casebrook, Parker wasn't prepared for what many Cantabrians have been going through for the past six years.
"It gave him a hell of a shock," Barry said. "He came downstairs and wanted to run outside, but I told him to just stay inside and that he'd be okay. We've done an earthquake drill now so he knows what to do."
Also on the card is rising Auckland heavyweight Junior Fa and Jeff Horn, the Australian welterweight ranked No2 with the WBO. Fellow Australian Shannon O'Connell, a top bantamweight fighting for an Asia Pacific title, is also on the card.
"Jeff Horn could be only a couple of fights away from a world title shot," promoter Dean Lonergan said. "His opponent Ali Funeka is unusual. He is a 6ft 1in welterweight.
Although Jeff will be fighting in front of a TV audience of millions, he really has an audience of one. Ringside will be Bob Arum, the promoter of welterweight stars Jesse Vargas, Manny Pacquiao and Timothy Bradley."
Fight card December 10, Vector Arena
Bout 1
John Parker (Akl, NZ) v Ash McConville (Chch, NZ)
Catchweight (94kg) - 4 x 3 minute rounds.
Bout 2
Junior Fa (Akl, NZ) v Pablo Magrini (Argentina)
Heavyweight - 8 x 3 minute rounds.
Bout 3
Shannon "Shotgun" O'Connell (Qld, Australia) v Laura Griffa (Argentina)
WBO Asia Pacific Super Bantamweight Title - 8 x 2 minute rounds.
Bout 4
Isaac "Royal Storm" Dogboe (Ghana) v Julian Aristule (Argentina)
WBO Latin and international super bantamweight title - 10 x 3 minute rounds.
Bout 5 - main undercard
Jeff "The Hornet" Horn (Qld, Australia) v Ali "Rush Hour" Funeka (South Africa)
WBO intercontinental welterweight title - 10 x 3 minute rounds.
Bout 6 - main event
Joseph Parker (Akl, NZ) v Andy "The Destroyer" Ruiz Jr (Mexico)
WBO world heavyweight title - 12 x 3 minute rounds.