Joseph Parker and Dillian Whyte at their pre-fight press conference in London.

Joseph Parker stands at the crossroads of his career. In one direction is a deep, dark, cavernous abyss from which there may be no way back: in the other a glittering highway to happiness paved with gold.

Which turn will Parker take? What does his fortune – in both senses of the word – hold? We will be a lot wiser late Saturday night (Sunday morning NZT) at a packed O2 Arena in central London when the 26-year-old New Zealander puts his 24-1 record up against the 23-1 mark of the formidable Dillian 'The Body Snatcher' Whyte.

No one is kidding anyone about the repercussions of this fight. For the winner there is a passport to riches, and a fast-track ticket to a world title challenge; for the loser the way back is almost too bleak to consider. A year, maybe two, trundling through mid-;level fights against no-name opponents, patiently trying to rebuild your tattered reputation is no one's idea of an existence.

Remember, not so long ago Parker was a world champion, with a WBO title belt to show for an unbeaten career. Then the Kiwi heavyweight ran smack-bang into the formidable form of Anthony Joshua who, with a little help from an out-of-his-depth referee, outboxed and outfoxed him en route to a unanimous points victory. Since then Parker has been counting down to this moment.

Now this genial Kiwi takes the route more precipitous. It's a high-risk, high-reward venture. A snakes and ladders-type scenario. If he wins, and does so with any degree of style or power, he will assuredly be back in conversations ending with the names Joshua and Wilder. Promoter David Higgins sincerely believes a 100,000-capacity showdown against the Brit champ at Wembley is a distinct possibility.

That might even make the supposed $6-7 million he banked from the first Joshua fight look like chump-change.

But even Higgins also admits it's a long way back from a second defeat on the bounce, both in front of a knowledgeable British boxing public who like the cut of Parker's jib but won't stay on board the Joe train should that Joshua stumble prove a more permanent malady.

That's a prospect that has to be acknowledged. Whyte, the south Londoner who packs a mean punch, has won his last seven on the trot since he, too, lost to Joshua in 2015. His last outing was an impressive victory indeed over Aussie Lucas Browne.

He's tough, he's experienced, he possesses a knockout punch and he's mean enough to stomp all over Parker's master plan at finding redemption. The Kiwi also noted his opponent's distinct lack of bluster at the Thursday presser, which suggested "hes taking this challenge seriously".

Joseph Parker has it all to gain as he looks to catapult straight back into the world heavyweight title conversation.

But we're told this is exactly what Parker wanted. To be tested. To jump right back on the horse and confront another brutal Brit. To get the opportunity to show that his strangely muted offensive performance against Joshua was the exception, rather than the rule.

At the press conference Parker promised to bring "bad intentions" and throughout his time in London he has been at pains to reveal a darker side of himself. He has talked about wanting to hurt his sparring partners, and a desire to inflict pain. Clearly this is a direct response to what many felt was a performance lacking ambition and anger against Joshua.

There are no excuses either. Everything has gone to plan for the Kiwi heavyweight who, remember, has never, ever, been knocked off his feet in this business. He looks big, strong and sharp, and every indication is he is in career-best form and fitness for this shot at redemption.

"I'm going to box smart and move well, because that's what got me here," says Parker. "I don't think he's the type of fighter who's going to make me move a lot. I want to throw heaps ... in order to win a fight you have to throw punches, and I'm going to throw heaps."

Adds trainer Kevin Barry: "Joe knows the significance of this fight. He knows what he's up against, which is a very dangerous, very powerful, very hungry Dilian Whyte.

"My fighter looks in great shape, There is something burning in Joe Parker's belly at the moment and he cannot wait to get into the ring with Dillian."

All the indicators are that Parker is the superior boxer. He went the distance with Joshua; Whyte was a TKO in round 7. The Kiwi appears to possess the slicker skills, the faster hands, the stronger jaw. Most notably, he has the better all-round game.

"We're both hungry for this fight," added Parker. "I want to be champion again. I feel like I've got more drive for this fight.

Whyte's trainer had some nice patter going on at the press conference. He said Parker had let all of British boxing down with his abject failure to deliver on his word against Joshua; "Dillian Whyte is going to rough him and tough him, persistently and consistently," said Mark Tibbs. "We'll walk him down, stalk him down and break him down. We have to eat, we got to live, man."

Whyte himself just shrugged and stayed away from anything boastful or wasteful. Previously he has tagged Parker a "coward" but you could sense that he has stumbled upon the significance of what he is about to do. He presented the dangerous face of a focused man at Thursday's pre-fight gabfest.

Both fighters have so much to gain. And even more to lose.