Former Test rugby player Mike Pyke says his 100th AFL game milestone is as much a vindication of Sydney Swans coach John Longmire's faith as justification for his gamble in switching codes.

Canadian ruckman Pyke will make his 100th appearance against Gold Coast on Saturday.

He made the switch to a code he had never played after representing Canada at the 2007 Rugby World Cup.

He admitted on Thursday he thought his Australian football career was likely to end in just its second season, in 2010, when the Swans signed fellow rucks Shane Mumford and Mark Seaby.

However Seaby suffered a serious ankle injury and Pyke flourished to cement a spot before becoming the club's No.1 ruckman last year, after Mumford left to join rivals Greater Western Sydney.

"I think it's probably sometimes a big risk for Horse (Longmire) every weekend when he picks me," 31-year-old Pyke said.

"I think the milestone is sort of vindication for his patience (with me)."

Pyke, played 22 tests for Canada and played against both the All Blacks and Wallabies during his four-year Test career, which ended in 2008.

Pyke revealed he thought he would not play more than eight AFL games after learning the Swans had recruited both Mumford and Seaby.

"I don't think I was close to giving up (on the AFL) but I thought maybe my time was up. I think had Mark (Seaby) not been injured that year, I would've probably looked to go back and play rugby" Pyke said.

An AFL debutant at the mature age of 25, Pyke isn't setting a deadline on his adventure, with his contract expiring next year.

"The decision gets made for you, and usually it's form and that usually correlates to how your body is doing," Pyke said.

"As long as my form is OK and my body is OK, I want to play as many games as I can."

Comparing Australian foootball and rugby, Pyke said they were very different games "but I think AFL in terms of a real toll on your body is more difficult".

After injury stalled his first season as the Swans premier ruckman following Mumford's departure, 31-year-old Pyke is enjoying one of his best seasons.

"I certainly feel more capable and comfortable with the role," Pyke said.