As a former All Blacks first-five and current head coach of South African franchise the Eastern Province Kings, Carlos Spencer is used to tough challenges, but getting in the ring with experienced boxer Monty Betham on Saturday night is among his biggest yet.
The pair, who showed off their impressive physiques when posing topless for the cameras in Auckland today ahead of their professional Fight for Life bout at the Claudelands Arena, will both carry some anxiety into the ring, however.
Spencer has some boxing experience - he has fought in two previous Fight for Life events with a draw against Awen Guttenbeil in 2011, and a victory over Jarrod McCracken a year later, but never against someone of Betham's quality.
"It's a personal challenge," Spencer, who arrived in New Zealand on Monday, said. "When Duco got in touch with me I didn't think I would put the gloves on again. Time isn't on my side, but I thought why not give it a shot. For me it's a one-off opportunity, they don't come around that often."
Betham, too, will feel the pressure. He has fought professionally six times, including against Shane Cameron in 2011 over six two-minute rounds, a bout in which he held his own but lost on points.
Betham, 36, said since then he had focused on his family, business and charity work, to the detriment of his physical condition.
"It's probably the worst shape I've got into in a long time," he said. "I got into some bad habits... so for me it was perfect timing and to come against someone who is a fierce competitor and someone who always comes in good shape - although probably down on experience he is a born winner - and I've been thinking about it daily."
He has dropped six kilograms, and has gone from 19 per cent body fat to 7 per cent, a measurement which must be similar to the extremely lean looking Spencer.
The 39-year-old Spencer, who played 35 tests for the All Blacks, has had few days off training since taking on the challenge three months ago. He said he had been getting up at 4.30am in order to train before his working day starts at 7am.
Spencer said he was well aware of former Kiwis league international Betham's skill as a boxer, but was focusing more on himself.
"I've had a look on YouTube, but I'm more worried about myself. I'm focusing on me, I don't want to waste energy on someone else. I'll go in there hopefully with a game plan that will help me survive four rounds.
"It's a massive difference," he said of the move from two-minute to three-minute rounds. "I'm going into the unknown, I know that. That's probably the biggest challenge.
I've just got to get in there and try to relax and take it as it comes. It's different to three two-minute rounds. I've trained and prepared for three-minute rounds, but it is the unknown."
Spencer also has a boxing victory over former England cricketer-turned-boxer and cage fighter Adam Hollioake to his credit.