The All Australian ruckman, who has been restricted to light running after groin surgery in November, said on Thursday his recovery was going "pretty well".
In response to suggestions he could miss up to eight weeks at the start of the season, Naitanui said, "It's my body. I know how it feels."
Asked by a reporter if he was suffering from osteitis pubis, the ruckman said, "No, I'm fine.
"I have been following my program. My goal is still round one. I'll see how I go and track along in the next few weeks."
He said his recovery program had been well planned, and as for his availability for round one, said, "If I'm not ready, I'm not ready. If I am, I'll put my hand up."
Naitanui joined teammate Josh Hill on Thursday to run a training session for the Flying Boomerangs, a personal development and leadership program for Aboriginal and Torres Strait Islander young men aged 14 -15.
The squad of 25 players will leave Perth on Thursday night to play two matches against a South African team in Potchefstroom and Durban.
"Me and 'Nic Nat' always have a bit of fun coming out here and just enjoying the experience," Hill said.
"I know a lot of players that do their own things off-field and they get out amongst communities and do stuff for Aboriginal kids.
"I enjoy it a lot … just give them a bit of knowledge of what I've had so far, and to be able to give back."
Hill, who has improved his running significantly this pre-season, said a selection squeeze was looming in the Eagles forward line with Mark LeCras and Mark Nicoski also impressing this summer in their return from long-term injuries.
"It's going to be tough for players to keep their spots, but I think that's the beauty of it … at the end of the day you can give as much as you can and hopefully get selected," he said.
"I know it's great having those two back out there and it's definitely making some of the younger guys work hard to keep their spots."
Nathan Schmook is a reporter for AFL Media. Follow him on Twitter: @AFL_Nathan