MERV Hughes jokes about the exact moment he knew it was time to retire. It was the moment Australian cricket coach Bob Simpson tapped him on the shoulder and said, "it's time".

For some, it's clear. For others, it takes that tap. It's different for everyone. There's no right or wrong, and no fixed time line.

For me it was an almost surreal moment. Playing against Carlton at the Gabba in round 13, 2007, in the last quarter of a close game, I suddenly thought to myself, "what am I doing out here?"

It hit me like a flash. And despite the fact that we won by 11 points, there was none of the normal joy. I couldn't wait to get off the ground and get away from the place and the subsequent nine weeks were hard work.

My mind had moved on. The flame that had been my competitive edge was diminishing and burning out.

It's a feeling I thought I'd never experience. The game I thought I'd play forever was beginning to slip away.

Do I wish I was still playing? Absolutely. There is no greater moment than running out with your team. I'll always miss that.

Nathan Buckley, Mark Ricciuto, James Hird, Glenn Archer, Chris Grant, Anthony Koutoufides, Luke Darcy, Chris Johnson, Chris Scott and James Clement will miss it, too. And all the other players who ended their careers last year under a vast array of circumstances.

Despite all the different reasons, there is one constant that helps players to decide when it's time.

It's about that fine line between success and achievement, satisfaction and dissatisfaction.

No doubt it is harder to retire when you feel you are leaving a job that is unfinished.

The dissatisfaction of an unfinished job and the need for more, or the belief that we deserve better, is a primary motivator for us all.

As much as I don't like to admit it, my level of dissatisfaction was not great enough to keep me playing. I'd achieved all I thought I could and wanted to pursue other areas of my life.

Not Robert Harvey.

Even at 36, despite all he had achieved in 20 years and 359 games in the AFL, he wasn't satisfied at the end of 2007.

So, in consultation with the St Kilda coaching and conditioning staff, "Harvs" opted for another year.

Super-veteran Harvey of 2008 will never be the same as the brilliant dual Brownlow medallist Harvey of 1998.

He will have his brilliant moments but they'll be less frequent. He won't play with the same consistency as he once did and he'll find it harder to recover from week to week.

So what? For Harvey it's not about him and his performance. It's totally and utterly about the team and what it collectively can achieve.

Harvey is motivated solely by the only honour that has eluded him — an AFL premiership.

As long as coach Ross Lyon was convinced, it was the right decision. And if Harvey was prepared to accept his role within the team, it was the right decision. Because only the coach and the inner sanctum really see what a player and a person of Harvey's ilk brings to his club and his playing group.

Irrespective of his age, Harvey is still a better player than a big portion of AFL players. He's worth his place in the side for all that he brings to the group.

A footy game lasts two-and-a-half hours. Or 1% of the week.

What Harvey does during that time is only a miniscule part of his total contribution.

If he has 15 possessions working on and off the bench, it's as good as 22 possessions for most other players. Or more. And even that's not what it's really all about.

It's something you can't measure in kicks and handballs. It's that indefinable quality that only champions have. That ability to be a positive influence on others just by how you go about your business.

It's what Harvey brings to the club. And what makes him a champion.

Everyone is in awe of him for his preparation, work ethic, reliability, trust, consistency and the family values he and his wife Danielle exude. And everything else about him.

For me, it's not about Robert Harvey lifting his standards. Ross Lyon, the players and Harvey himself have accepted the role he will play in the premiership pursuit.

It is now time for the rest of us as spectators to realise and accept that, and to quit measuring him on his past feats.

So let's sit back and enjoy the final year of a true champion.