Martz - who regularly answers questions with "yes, sir" - may also be the politest opponent Parker has faced.
However, his efforts to help Povetkin prepare for his recent 12th round TKO of Poland's Mariusz Wach has him believing he can match it with the world's best.
"Before I got in there with Povetkin, I was putting these guys up on a pedestal, and they're really good boxers, but they're not really anything more than that," he said.
"I did very well, he never hurt me, and I thought I did a really good job.
"I sparred 40 rounds with him and they were very happy with the work I gave him. They kept me the whole time and they send guys home if they don't and they seemed really appreciative."
Since returning to the United States, Martz went to a secluded training camp in California, Pennsylvania, where his focus shifted to preparing for Parker.
"My camp is out in the woods where no one bothers me and my trainer takes very good care of me.
"He cooks all my meals, he follows me in the car for road work, and we do our training in the evening - whether it be sparring, shadow boxing, hitting the bag or the speed bag - and he takes care of my laundry.
"So it's really eat, sleep and box for me right now and has been for the last three months.
"I have all the respect in the world for Joseph, especially because he's 23 years old and he's doing what he's doing, and it's a great opportunity to be able to get in there with a guy like that."
This is Martz's first visit to New Zealand and he hopes to take in some of the countryside he has seen and read about.
"I understand they did a lot of the filming for Lord of the Rings there, and I'm a big fan of those movies. I've read all the books and from what I can see from the films, it's a very beautiful country."