Heavyweight boxer Francois Botha says Sonny Bill Williams is "stupid" for figting him Quade Cooper and Sonny Bill Williams watch on ringside. FRANCOIS Botha says Sonny Bill Williams is "stupid" for fighting him and a fairer contest would have been against his son, a 70kg amateur boxing star. Botha, the "White Buffalo," arrived in Brisbane on Saturday ahead of Friday's WBA International heavyweight title bout against All Blacks centre and Sydney Roosters recruit Williams at the Brisbane Entertainment Centre. The mind games have already started and it seems inevitable the verbal fight will be won by Botha. The 44-year-old South African, who sleeps with a pet Chihuahua named Peanut, admitted he respected Williams' courage. Evander Holyfield (L) hits Francois Botha in the first round of their heavyweight bout April 10, 2010 in Las Vegas. "He's got a lot of big balls, and I don't mean rugby balls," Botha told The Courier-Mail. Why is he taking this chance? He should stick to rugby because I will hit him so hard that when he tries to catch the ball, he'll just miss it. When I catch him he's going to go. I'll drag him to deep water and let him drown. He's never fought a guy like me, it's stupid. Sonny should have fought my son, my son would kick his arse and he's not even a professional. I don't know what planet he (Williams) is from but I don't think he's from planet Earth. Botha (48-8) has fought a who's who of heavyweights in an outstanding 23-year professional career. Names like Mike Tyson, Lennox Lewis and Evander Holyfield decorate his impressive record. He has lost his last three fights, but gone past 10 rounds in each one. Sonny Bill Williams' former manager has called into question the player's deal with the Roosters. Williams (5-0) is decidedly the better athlete, but has not been past six rounds so far in his career. He won his last fight against Clarence Tillman in a first round knockout, displaying solid boxing technique and power. Botha was adamant Williams had no idea how taxing a 12-round fight could be and that his talented but inexperienced son Marcel "Mayhem" Botha would also beat him. "In real life, he should never have an opportunity to fight a guy like me with just five fights to his name," he said. I'm only taking this fight because of his notoriety in rugby. Williams has repeatedly said he would retire if he was knocked out in this bout. "He's already retired then," Botha quipped.