Following West Coast Eagles' thrilling victory over Adealide on Sunday, it was confirmed that Petrie would hang up the boots after the upcoming finals series.

The former St Patrick's College student, who played his junior football with the Ballarat Swans and North Ballarat Rebels, featured in 316 games with North Melbourne before being delisted by the club at the end of the 2016 season.

But the Eagles handed him a lifeline via the rookie draft, and the 34-year-old has played a key role in getting West Coast into the finals.

With Nic Naitanui (knee) out for the season and Scott Lycett (shoulder) limited to just one game, Petrie has been forced to play as an undersized ruckman during his 14 games this year.

He also spent a stint as the club's key forward while Josh Kennedy was missing through injury.

A broken hand in the season-opening win over his former side was a big setback, but Petrie has been a strong contributor ever since returning to the side in round 10.

"I think he's been really embraced by our supporters," Eagles coach Adam Simpson said.

"And I think they know him for who he is as a person as well. To do that in 12 months is a credit to him and his family."

West Coast Eagles will take on Port Adelaide in an elimination final on Saturday, September 9.