But Peters said he felt he could give them a good run for their money, especially in his hometown.
"I know the course really well," he said.
"This year I would not be classed as a favourite but I will have home advantage and home support and knowledge."
He said his form going into the event was good.
"[My preparation] has been pretty good. I've been training pretty well and have had some good race results leading in," he said. He has been racing the national cup series, which is a build-up to the national champs, and finished second in Taupo last weekend behind Gaze.
Peters said he was rapt with how he raced at the Taupo event, and was ready to put everything on the line tomorrow, with the elite race starting at 2pm on Radio Hutt Rd, top of Nursery Hill.
Peters races for the Rotorua-based mountain bike team NZXC Racing, and he thanked all their sponsors for the support.
NZXC rider Kate Fluker (Queenstown) will also be looking to defend her title in the women's cross country race this weekend.
Gaze just edged Cooper to win the nationals last year then Cooper finished ahead of Gaze at the Commonwealth Games a few months later, with the pair taking gold and silver.
The Mountain Bike National Championships will feature cross-country racing tomorrow and downhill racing on Sunday, with national titles up for grabs in both disciplines.
The downhill racing will be held at Skyline on Mt Ngongotaha.
*A downhill preview for the Mountain Bike National Championships will be included in tomorrow's Rotorua Daily Post.