"The All Blacks aren't as strong as they were last year, they've lost some very key players," Eales said.
"They're still a strong team, the All Blacks are only ever the best or the next-best team in the world no matter what the rankings say. They can always beat anyone on their day without question.
"But they have slipped a bit from last year. They haven't got that same aura of invincibility about them."
The former goal-kicking lock believes the withdrawal of All Blacks skipper Richie McCaw leaves the side further exposed but still considers the Kiwis an even-money chance against Robbie Deans' men.
"I think it shapes up as a really good Test. They're still missing Richie McCaw which is a big loss for them, no question about that, so it's going to be tough," he said.
"It's a 50-50 game, I don't think the All Blacks are favourites and I don't think we're necessarily favourites."
Pressed on the All Blacks' frame of mind heading into the Bledisloe Cup blockbuster, Eales suggested the disappointment of another failed World Cup bid last year still hovers over the Kiwi camp.
"There's no question they've got a lot of pressure on them. I'll reiterate they're a very, very good team but they do have pressure on them," he said.
"It would be very difficult to front up to the campaign this year in light of the disappointment they had last year.
"I mean the Wallabies had disappointment, both exited at the same time (the quarter-final stage), but the expectations around the Wallabies outside the team themselves were nowhere near as high as they were within the All Blacks.
"And to have something taken away from you when everyone else thought it was going to be yours and you probably thought it was probably going to be yours - there's no given (in rugby), but that does hurt.
"And, psychologically, sometimes it's hard to start again and particularly with the same coaching staff."