Wallabies openside Michael Hooper was the dominant figure in the hosts' 30-28 victory in the first Test in Perth, ruling the contest on the ground including winning one game-changing turnover.

Underhill is now poised to replace Tom Curry, who suffered a concussion at Optus Stadium, and the Bath back-rower insists dominating the breakdown will be key to ending England's four-match losing run.

"We controlled areas of the game pretty well for a decent chunk of the game but ultimately penalties and discipline cost us," Underhill said.

"Whether the breakdown was more competitive than we thought it would be or not, we didn't adapt to the interpretation at the breakdown.

"Hooper is obviously a big breakdown threat. It's not a case of man-marking him but as a team you are acutely aware that if he's around the breakdown it's highly likely he'll be competing. You have to shift him early because he's good over the ball."

Curry was ruled out of the tour after suffering a concussion in the first Test, his third head knock in the past six months.

Underhill was sidelined for more than two months after suffering back-to-back concussions either side of Christmas. His empathy for Curry is mixed with concern over the growing size of the collisions.

"At Test level Tom is a machine and I'm gutted for him that his tour is over early," Underhill said.

"Rugby is a more physical game than it has ever been. There are big athletes who move very well and at Test level you don't have a lot of time to react. The collisions are quicker."

Despite his concussion struggle, Underhill believes the tackle height laws have made the game safer and more entertaining.

"The laws around tackle height and stuff are having a good effect on the game but ultimately if you tackle lower it is harder to affect the ball speed, but ultimately it creates a more entertaining game. I would argue that would be a good thing on the whole," Underhill said.

"I would like to see players working with refs and vice versa because at the moment I think maybe it would be better for the game if there was greater understanding."

Australian Associated Press