Wallabies hooker Tatafu Polota-Nau says he will consider retiring or taking a long break from rugby union if he suffers another bad head knock.

Polota-Nau, who has a history of concussions, was forced off after copping a knock in the opening minutes of the Waratahs' Super Rugby win over the Brumbies in Canberra on Friday night.

The 50-Test veteran altered his fearless, sometimes literally head-first, tackling technique last year and had no more issues, but he missed two games earlier this season after suffering a head knock in a training incident.

Polota-Nau 29, said it was a case of welfare first and sport second.

With a World Cup just over four months away, he said the latest head knock was a concern.

"At the end of the day it will come down to taking those right precautions, because if I do, for instance, get another head knock, then I will probably have to consider either taking a long stint off or even hanging up the boots," Polota-Nau said on Monday.

"There's more to life than just rugby, but at the same time I still feel like I've got unfinished business with rugby itself."

He will go through concussion protocols before being cleared to play against Western Force in Perth on Saturday.

"With my previous one (head knock) the symptoms were delayed, whereas I'm not too sure if they are going to be delayed (this time)," Polota-Nau said.

"But at the same time I'm feeling great. I actually wish we could play the Friday game again.

"If I'm right, I'm right if I'm not, then I'm not.

"I think the great thing with not just the Waratahs, but the ARU as well, are really caring about my welfare."

The Waratahs are now just one point behind the Australian conference-leading Brumbies with a game in hand after recording a third straight win.

"There's definitely a lot of improvement we can take out of the Brumbies game, but I think the effort was always there, which is great to see," Polota-Nau said.

"Just a few tweaks here and there in terms of our approach in both attack and defence and I think we'll get the job done."

AAP