The former world champion fights Massey tonight (21.01.23) and knows that his dreams of more world title success will be over if he is beaten by the underdog.
Parker said: "Let's face it, if I lose I will be way down (the standings). It will be like, 'Where is Joseph Parker?', I'll be out of the picture."
However, the New Zealand boxer is refusing to give defeat any thought.
He said: "I'm in great shape, I'm ready to go. When I'm sleeping well and feeling good I am dangerous. I've put in the work, made the sacrifices, because I know what it takes to win."
Massey has stepped up to heavyweight to take on Parker in Manchester and the favourite has vowed to teach his rival a lesson.
Parker said: "I'm going to smash him.
"He's got big balls I'll give him that. But there are divisions in boxing for a reason. I'm going to be the bigger man. I'm going to fight like the bigger man, back him up and push him back. I'm going to make him think about if he really wants to be in the heavyweight division."
Parker is unsure of what to expect from his opponent and is refusing to underestimate the challenge.
He said: "I'm approaching it like every other fight, like it's the championship of the world. When you approach a fight like that and you take every fight seriously, you're going to be in the best condition and that's what I've done in this camp.
"Every fight you want to look good and you want to make a statement but when you go looking for it, it doesn't really happen. I want to go out there, enjoy myself and just execute what I've been doing in camp."