Which brings us to Kiwi prospect Parker who will meet Williams in Oberhausen, Germany, on the undercard of Klitschko's world title defence against Australian Alex Leapai next Sunday.
"For whatever reason it is, they decided to give Joseph a real test," Williams said.
What makes Williams so testing is his granite chin. He has lost 13 times but only one of his fights was stopped early and that was because he suffered an ear injury.
Parker's power has steadily improved and recent knockout wins over Afa Tatupu and Francois Botha showed he could throw bombs. But putting Williams on his backside would be notable.
The 22-year-old South Aucklander has never fought more than six rounds - Brice Ritani-Coe took him the distance in California last year - so having a 10-round bout will be another step in Parker's development.
Parker's handlers have selected this fight carefully because they view it as one he can learn from while maintaining his perfect winning record, which stands at 7-0.
But that does not bother Williams, who concedes 12cm in height to Parker.
"I'm going to go in there and give him an ass whooping."
Despite Williams' concerns that he can't find enough willing opponents, he fought twice last year and had a couple of bouts in 2012.
Coming in to the ring against a highly touted prospect could give the impression Williams is just a stepping stone but he doesn't take that angle.
"I've seen it all," Williams said. "There's nothing that Joseph can show me that I haven't seen before. So they need to be worried about what I'm going to be doing. I'm definitely not worried about them. I come to do my job and whichever way it comes, I'm going to do it."
For all of Williams' tough talk, he doesn't have the backing of former world heavyweight champion Hasim Rahman who has been impressed with Parker during the early stages of his career.
"I think he's got a good future ahead of him," Rahman said. "I'd like to see if he's able to stop Sherman Williams because if he can stop him that would be impressive. I know he's going to beat him, I just want to know in what fashion he beats him. That will tell me a lot."