If the fifth-ranked Aussies have peaked, how can they climb to the top of the mountain?

Australia vice-captain Brad Haddin is one of seven players in the side aged in their 30s, but he says it’s just a number.

He would say that, having smashed 325 runs at an average of 65.00 to be the third-leading scorer in the first three Tests of the five-match Ashes series.

Australia can jump two spots to third on cricket’s rankings if they can win the Melbourne and Sydney Tests.

Haddin says captain Michael Clarke’s men have lost none of their enthusiasm for a series sweep, despite massive celebrations in Perth after last week’s win allowed them to regain the urn.

The straight-shooting Haddin is putting no time limit on his future in the game and says the No.1 ranking is the team’s ultimate goal, although he admits they may have peaked.

“Maybe,” Haddin told a news conference on Tuesday.

“It’s not something we think too much about. If you’re performing and keep challenging yourself to be the best cricketer you can and contribute to this group moving forward, we’re comfortable with that.”

Haddin played one of Australia’s four Tests in India in March and that call-up came after an injury to Matthew Wade.

The 36-year-old Haddin is now back as a key figure in the team, having played in all eight Ashes Tests in 2013.

“There’s a lot can be made of age,” Haddin said.

“If we talk too much about age, I wouldn’t be standing here.

“I’ve been told on a number of occasions I’m too old.

“Age is not something that the players are worried about.”

Opener Chris Rogers admits he can’t afford to have two or three bad Tests in a row because people will start to say he’s too old at 36.

Ryan Harris is Australia’s pace spearhead at 34 but a chronic knee injury means his playing future is constantly under the microscope.

“As soon as I stop challenging myself out on the training paddock to become a better player is when I give the game away but I still see a lot of cricket in front of me,” Haddin said.

Peter Siddle, Haddin and Shane Watson had played in three losing Ashes campaigns before finally tasting a series success in Perth.

Haddin said it was a special moment.

“I’ve been on the end of a few hidings from England so from my point of view it’s not that hard at all,” Haddin said of his motivation levels.

“I feel as comfortable as I have in this environment.

“It’s important to play as long as you can with the same group of guys.

“You get to know each other … how to get the best out of each other.”