While it's premature to suggest Hayne has the consistency in his game to challenge either Slater or Inglis for the Australian fullback position, he has shown in the past and for all of this season that, at his best, there are few better in the game.

There's been plenty of debate leading into this year's State of Origin series over where the Hayne plane will land in the Blues' line-up.

He can play on the wing and in the centres, but there's no doubt fullback is where he's at his destructive best.

Slater, who returned to form in a blistering two-try performance against South Sydney on Friday night, believes the added responsibility of the captaincy has done wonders for Hayne's game.

"He is a great player," Slater said. "He is an outstanding player and is playing some really good football this year. He seems to have matured a lot with the captaincy."

Kangaroos coach Tim Sheens took a gamble during last year's World Cup, playing Hayne in the unfamiliar centre position. It proved to be a masterstroke, with Hayne forming a lethal combination with winger Brett Morris, producing the type of football that Slater believes saw him earn the tag as the Kangaroos' most valuable player.

"In the World Cup he was probably the best Australian on tour," Slater said. "There's a lot of debate over where to play him [in Origin]. It doesn't matter - he's out on the field. He'll be dangerous if he's out on the field."

Slater has been heavily scrutinised after a slow start to the season for Melbourne, with many wondering if his best is now behind him. But, in a timely boost to the Maroons' aspirations of making it nine Origin series triumphs on the trot, Slater overshadowed Inglis to lead his side to a 13-point victory over the Rabbitohs at ANZ Stadium on Friday night.

While Slater admitted his form had been below par at the start of the season, he insisted that age and ability had not been a factor, rather the interrupted preseason after going under the knife for a knee injury. "I've been around the game long enough to respect that everyone has got a role to play in this game and I understand that being a high-profile person that I'm going to be talked about a fair bit in the media, whether that be good or bad," Slater said.

"If I'm not playing up to my standard then obviously I'm going to attract a little bit of criticism. I know where I'm at and I know where I've got to get through.

"Certainly the fitness affected me in the first six weeks of the competition. That was always going to happen.

"You can't substitute running. No matter how much boxing or alternate swimming you do, you can't substitute running - and that was taken away from me this preseason due to a knee injury."

Despite the barrage of criticism, Slater was adamant it had no effect on him.

"It's easy to fall in that trap and it doesn't take long for people to turn on you," Slater said.

"I'm aware of where I need to be and the standards I need to uphold when I take the field. When the day comes when I feel I can't do that, that will be the day [I give it up], but that day's not here yet."