Veteran heavyweight boxer Francois Botha says he has spotted flaws in the style of Sonny Bill Williams ahead of their WBA International bout in Brisbane on Friday.
"He's a very basic fighter and in terms of international experience he's still green," Botha said after tipping the scales at 115.25kg on Thursday.
"He's got no balance and doesn't have any punching combinations. He's straightforward, so there's a lot for him to learn."
Botha, however, remained somewhat wary of Williams, who is better known as an All Blacks rugby player, but is also the current holder of New Zealand's heavyweight title.
"He's a big guy, he's strong and could land a lucky punch, so I will be careful," the 44-year-old South African said.
"If you keep him busy you'll expose his lack of boxing skills."
Since his arrival in Australia a week ago, Botha said he had eased up considerably on gym work in an effort to stay strong for the bout.
"I've done all the donkey work back in South Africa, and it's just a matter of recharging the batteries. I've regained all my strength and I'm ready to kick ass.
"It's been very humid here and the bright lights above the ring could make it even hotter, but I've fought all over the world and I'm sure I can adapt to the conditions.
"It could be energy-sapping under the lights, but I'm feeling good to go."
Williams, the local bookmakers' favourite, was less talkative ahead of the fight, and he said he would prove his worth in the ring.
"The showman's come out in him (Botha). He's been talking it up," Williams said.
"It's a privilege to fight him, but I won't be asking for his signature inside the ring."
Meanwhile, Australian rugby flyhalf Quade Cooper will also be making his professional boxing debut by fighting Barry Dunnett in a cruiserweight bout.
"It's getting a little bit tense, the atmosphere of this whole thing," Cooper said.
"I've learned a whole lot from this experience. I'm in great shape. Hopefully I'll finish up on top, but I'm not here to predict anything. I'll get in there and do my best."