Tatafu Polota-Nau is now letting his head rule his heart as he finally notches his 50-Test milestone for the Wallabies.

Kamikaze hooker Tatafu Polota-Nau was a schoolboy academic who excelled in chess before becoming the Wallabies’ Mr Wreckless.

Now, after nine seasons and countless serious injuries, the Tongan powerhouse believes he can produce his best, and remain on the field, by finally allowing his head to rule his big heart.

Rushed back from a torn knee ligament to play his 50th Test this weekend, Polota-Nau is again using his smarts by tempering his punishing approach to rugby.

But the Wallabies need both to overcome a fierce Argentine forward pack in Saturday night’s Rugby Championship clash on the Gold Coast.

Polota-Nau will remain abrasive and powerful but will show some self-preservation to ensure he can play out 80 minutes and rack up his Test appearances more regularly.

“Through my tenure it’s been about putting the heart on your sleeve, no matter what,” he said. “But you also have to be smart about it.

“The heart ruled the head on most times.”

A self-confessed “nerd” at Granville High School, who also competed at state level in chess, the NSW rake’s adaptability this season ensured he was an ever-present through the Waratahs’ title-winning campaign.

“He’s literally put his body on the line and the intelligence he’s applied to everything else in his life he applying to his football now,” said Wallabies coach Ewen McKenzie.

“There’s a little bit of self-preservation now.”

McKenzie, who recruited Polota-Nau to NSW from the Brumbies in 2005, showed his own high regard for the punishing rake by reserving a special praise for rugby’s “true servant” at Tuesday’s team naming.

He felt his 50-Test milestone should have come far earlier.

“I remember Herculean, physical efforts in terms of tackling and you pay a price for that,” McKenzie said.

“He’s older and wiser now and I’m sure we’ll see him around for a while yet.”

It’s Polota-Nau’s experience and scrummaging ability which has seen him replace James Hanson, while Ben McCalman beat Scott Higginbotham to the No.8 jersey due to his similarity to the injured Wycliff Palu (head knock) in a “like for like” call.

McKenzie is confident in-form prop James Slipper, one of five players laid low by a gastro bug, will overcome a shoulder-neck injury in time to take his place at Cbus Super Stadium.

In the only backline change, NSW winger Peter Betham was preferred ahead of Joe Tomane for his second Test start after Adam Ashley-Cooper aggravated his own neck problem in the 24-23 win over the Springboks.

Wallabies: Israel Folau, Peter Betham, Tevita Kuridrani, Matt Toomua, Rob Horne, Bernard Foley, Nick Phipps; Ben McCalman, Michael Hooper (capt), Scott Fardy, Rob Simmons, Sam Carter, Sekope Kepu, Tatafu Polota-Nau, James Slipper. Res: James Hanson, Pek Cowan, Ben Alexander, James Horwill, Scott Higginbotham, Matt Hodgson, Nic White, Kurtley Beale.