By his own admission, Petrie made a slow start to 2014 and for the first time coach Brad Scott began to field questions from the media about the 32-year-old's performance.

However, any queries about Petrie's form quickly faded into the second half of the season as the 197-centimetre goal-kicker finished with 50 goals for the year (the second most of his career) and the Roos, with Petrie as their No.1 forward, advanced to the second last week of the finals.

The debate has caused Petrie to ponder why those in the industry have a tendency to look at 30 as being a "scary number", and form the automatic belief that anyone past that age can "fall off the cliff" at any time.

Petrie, who will not turn 33 until October, has experienced a different kind of pre-season leading into 2015, having not joined in full training until last week.

It will be the first time in his 14 years at North that Petrie has not done all of the pre-season – a situation arising from a deliberately cautious rehabilitation program from minor surgery on the ankle he has predominantly jumped off and landed on his entire career.

The Roos big man is just now starting to field questions about whether he will be "rested" in games and needs to be "managed" during the pre-season.

But to Petrie, 30 is "just a number".

"All that number does, if your form starts to go downhill and your body starts to pack up, then it just gives people a reason to justify their argument that you are getting past it," said Petrie, discussing his view on playing at a stage of his career when  "veteran" or "ageing" will precede his name  in the media.

"But if I've never had a soft-tissue [injury], this is my first operation in 15 years post season, so I guess you'd call that the first sign of any sort of wear," he said.