"Everyone knows how competitive we both are ... I'll be looking to hit his sore knee and Luke will be aiming to punch me in the back," Chaffey quipped.
While both are expected to weigh in around the 95kg mark Ottley will have a four- centimetre height advantage.
The Ryan Whittaker-trained Ottley is following former Havelock North teammates including Graham Hawkins and Andy Barham into the ring and like the Dan Digby-trained Chaffey won't be short of support.
"Aaron is encouraging everyone at the rugby club to buy a table and come and watch me get taken out," Chaffey said referring to fellow former Magpie and Taradale rugby player Aaron Hamilton.
An eight handicapper at golf, Chaffey, said he is enjoying the training and if the fight goes well he may become a regular on the charity boxing circuit. Ottley said the aerobic aspect of the training for the three two-minute round bout is tough compared with rugby trainings but he is relishing the benefits.
Event organiser Patrick O'Brien is thrilled the fourth annual BFL will proceed after fears last year's one may have been the last because of a lack of financial support. In addition to Pak 'N Save coming on board as the major sponsor, the Sport Hawke's Bay-sponsored Blue Team will support the Prostate Cancer Foundation of New Zealand and the Raisey's Original-sponsored Pink Team will support The New Zealand Breast Cancer Foundation.
O'Brien, the 2012 Ngati Kahungunu Sports Awards Administrator of the Year award- winner, will take on Hawke's Bay kickboxer Shaun Rankin in one of 10 confirmed bouts.
Hawke's Bay's Pane "The Punisher" Haraki will take on fellow world champion kickboxer Mike Angove of Auckland in the feature fight. Angove has battled cancer in the past.