SHANE McInerney will become just the fourth AFL umpire to take charge in 400 games when he walks on to the MCG for Saturday night's Hawthorn-Geelong clash.

His senior umpiring career started in 1994 and to get an indication of how the landscape has changed, it's worth noting that game was played at what was then known as Optus Oval (now Visy Park, home of the Blues) and the respective coaches of Carlton and the Sydney Swans were David Parkin and Ron Barassi.

It is 13 years since either coaching legend has been involved in the AFL in any official capacity.

In an interview in this week's AFL Record, McInerney put his longevity down to "persistence and patience" as well as his ability to keep pace with the way the game has evolved.

Colleagues say his career has been marked by perseverance and an ability to adapt. AFL umpires' coach Hayden Kennedy said the 43-year-old remains coachable even after all these years.

"He's always been a really good manager of the game, but now he's doing a strength program to try to get better. He's very strong-minded and still trying to achieve the very best he can this late into his career," Kennedy said.

McInerney, who has umpired 24 finals including the 2004 and 2007 Grand Final, admits it is getting tougher. "What was easier in my mid-to-late 20s is harder now and if you don't put in the physical preparation, then it won't happen for you in game-time as your body slowly deteriorates," he said.

"But it might be a bit mental as well. You have to train the mind as well as the body."

After more than 20 years of toting a whistle, McInerney still loves the game. "Every game throws up particular challenges, for example, making sure with taggers and run-with players that everyone gets a fair run at the footy. Interpreting the different strategies clubs use to find their competitive edge can be a challenge.

"That creates grey area in our game. All rules are open to interpretation but it is the flexibility in that interpretation that keeps it interesting and allows the game to grow. And rule changes and natural evolution have allowed the spectacle and entertainment value of the game to grow."

* Kennedy (495 games), Rowan Sawers (410) and Stephen McBurney (401) are the others to break the 400-game mark.