WORLD rugby chiefs must not abandon "history and tradition" in favour of staging Six Nations matches in the USA, according to former Scotland captain Alastair Kellock.

Glasgow lock Kellock captained the Barbarians to a thrilling 40-36 Twickenham defeat to Australia on Saturday, showing his Test class despite being overlooked for Scotland's autumn campaign.

International Rugby Board chief executive Brett Gosper said he would welcome Six Nations action being staged in America, following the sell-out Chicago clash between New Zealand and the USA.

After upholding long-standing rugby values as the Barbarians pushed Australia to the limit in London, Kellock warned against the sport making too many changes too soon owing to its growing financial benefits.

"The game is changing; it's becoming more commercial, which is a good thing," Kellock said.

"It's getting more viewers in from all over the world.

"The history and the tradition of playing Six Nations matches at the Millennium Stadium or playing at Murrayfield, to give just two examples, is also very strong.

"So whatever happens I'm lucky enough not to have to make those decisions!

"But we need to remember the history and tradition of our game, and that's what we showed at the weekend against Australia.

"I believe you've got to wait and see how the game with the All Blacks goes over there, the pick-up and the noise after it.

"And then it's important to drip-feed it.

"Let's not try and run and talk about Six Nations games over there until we've taken a few steps forward and talked about some more exhibition and friendly matches."

Meanwhile, New Zealand dispatched the USA 74-6 at Chicago's Soldier Field on Saturday, the All Blacks stopping off en route to their northern hemisphere tour.