Samu Kerevi reveals the reason for his departure to Japan

Wallabies centre Samu Kerevi holds no grudges with the national body after confirming a three-year deal with Suntory in Japan's Top League from next season.

The Queensland Reds captain will farewell Super Rugby when he runs out in Canberra against the finals-bound Brumbies on Saturday and, under current rules, will be ineligible for Wallabies selection beyond this year's World Cup.

The 26-year-old tossed and turned on the decision but said his brilliant form this year - and any subsequent late push from Rugby Australia to salvage a deal - wasn't enough to make him go back on his word.

"I'm not disappointed at anyone to be honest," he said of the agreement he made "a bit later" than the season's first round in February.

"They've (RA) got a lot of things on their table; I'm not the most important thing out there - that's okay with me.

"It was more my word (to honour the contract) than anything."

A $400,000 yearly gap in salary - $800,000 compared to $1.2 million according to Fairfax - reveals the uneven bargaining power of both organisations.

Things were complicated though when Kerevi's stock soared this season.

The destructive centre thanked hard-nosed defence coach Peter Ryan for improving his weaknesses, while he is topping the charts in carries and defenders beaten and sitting second in offloads and fifth in clean breaks.

He has proved to be the heartbeat of the Reds' campaign and will arrive at Japan's World Cup in September as one of Wallabies coach Michael Cheika's trump cards.

But while his value to Rugby Australia may have risen, Kerevi hinted negotiations have moved too slowly to change the equation.

And the chance to spend time with younger brother Jone, who is based in Japan, meant that a change of heart was never likely.

"I missed out a lot of his life (while growing up in Brisbane)," Kerevi said.

"I prayed about this situation and what my family needed . .. I want to see his growth, teach him how to shave, little things like that I missed out on."

"I didn't really want to leave in terms of what I wanted to do here in Queensland still ... my little brother was the main reason why."

The Reds' (6-9) finals hiatus will continue in coach Brad Thorn's second season in charge.

Kerevi is adamant he sees a "championship team" at Ballymore in the future and still entertains a return to Brisbane after 2023.

- AAP