Sonny Bill Williams says his dramatic improvement in boxing has surprised himself and made him take the "massive risk" of fighting former world title challenger Frans Botha on Friday night in Brisbane.
Williams (5-0, 3 KOs) faces the "White Buffalo" at the Brisbane Entertainment Centre in a 12-round contest for the WBA international title - which will give the winner entry into the top 15 of this governing body.
"Before (the last fight) I didn't think I had too much ability," Williams says.
"I just tried to use my athleticism.
"It was a real eye-opener. I just seemed to pick it up.
"It surprises the heck out of me. Boxing's not in my blood.
"My old man probably threw a couple of overhand rights in the pub but that was it.
"It's a massive risk but its massive reward as well."
Williams said he'd always put himself out of his comfort zone during his career and at 27, this fight would determine his future as a boxer.
"If I want it to come the fruition - the dream of doing this in the future - I need to do this."
Williams credits Tony Mundine with developing his ring acumen but, after his manager Khoder Nasser's fall-out with Anthony Mundine prompted a change of cornerman, the former All Black says his improvement has continued under the tutelage of Mick Akkaway.
"We sought out Mick's help and it has grown from there," Williams says. My confidence has grown. That's why we're stepping up in calibre of fighter."
The Sydney Roosters star has battled through a pectoral injury, which delayed the bout from its original November date, and admits his training has been hampered slightly, but insists he is now fully fit.
After attacking Williams' credibility yesterday, Botha (48-8-3, 29 KOs) was in far more polite mode insisting the movement of rugby players such as Williams and Quade Cooper into boxing is beneficial to pugilism.
"I wish more sportsman would come into the boxing arena," Botha says.
"It is really reviving boxing."