The 26-2 Parker has had just one fight in 2019, a TKO of Australian Alex Leapai in Providence in June. Chisora has a 31-9 record with victories over Senad Gashi and Artur Szpilka this year.
The bout will be the co-main event on the card headlined by a super-lightweight world title unification fight, and shapes up to be a turning point in Parker's career - for better or for worse.
Speaking to the Herald, Parker's manager David Higgins said a win opens a lot of doors for Parker, while a loss makes the road back to the top a whole lot longer.
Both fighters are household names in the UK and are both well respected. Chisora has become a fan favourite in his homeland due to his knock out power and trash talk.
"Styles make fights," Higgins said. "They're a good match up.
"Some think Chisora, some think Parker - it could go either way. So it's got all the ingredients: two stars, parochialism, New Zealand versus England, you've got the good guy Parker versus the bad guy Chisora, it's got competition... so it's got all the magic ingredients.
"For Parker, winning is everything. There's a lot at stake. If he loses, it's a very long and hard road back, and he knows that. But if he wins, he's right back at poll position. Beat Chisora in his home country, and that's a statement. Then Joseph can quite rightly call out the big boys again - the Anthony Joshua's of the world, Deontay Wilder, Tyson Fury, Andy Ruiz.
"So the focus is on 26 October, win and Joseph can be calling out those guys again."
Higgins said a win for Parker could lead him to a "mega stadium event" against one of the big names in the division work millions.