He began his career as a forward, but Heath Grundy will celebrate his 100th game this weekend as an important cog in the Sydney Swans’ defence.

Grundy, who was a rookie elevation in 2005, played his first three seasons with the Swans in the forward-line, but was unable to secure a regular position.

The decision to mould Grundy into a key defender was one he credits for this longevity in the game.

“A few times I questioned myself as to whether I’d be able cement my spot in the team, but over the last few years I’ve definitely done that and have been able to finally play 100 (games) which is really exciting,” Grundy said.

“I’m not really too sure (why it didn’t work in the forward line), but having gone down back I think I’ve learnt a lot from there so it’s just where I play my best footy and I’ve gone from there.

“It’s not til this week that it’s really hit home, so I’m really happy.”

The 25-year-old - who turns 26 tomorrow - from South Australian club Norwood said he wasn’t sure who came up with the idea of moving him into defence, but said he was provided with plenty of support from the Swans’ coaching staff along the way.

“I’m not really sure who made the decision but I suppose Roosy (former coach Paul Roos) and Horse (John Longmire) had a big part in that and I’ve had some coaches along the way like Peter Berbakov and Johnny Blakey who have definitely helped me out down there and I’ve learnt a lot from those guys,” he said.

“I learnt quite a bit (from Roos) and he was really good to me and I had some off games at times and some really good games, but he kept me down there and gave me some big jobs…so I got a lot out of him.”

When Grundy was recruited to the Swans, he faced the challenge of breaking into a forward line that was already complete with former stars Michael O’Loughlin and Barry Hall.

Swans coach John Longmire said Grundy’s resilience to re-build himself as a player was something he should be proud of.

“(When he first came to the club) we played him as a forward. He was up there with (Michael) O’Loughlin and (Barry) Hall, a couple of massive personalities who probably told him to get out of the way most of the time,” he said.

“He was able to kick goals at different times and do quite well, but it wasn’t until he was moved down to defence that he was really able to establish himself as a consistent player.

“Now he’s playing on some of the best players in the competition. Heath is 102kg and is in our top 10 runners at the club, so he works really hard on his game.”

Grundy hopes his 100th game celebrations will be marked with a better performance than last week’s effort against the Saints.

He said the team were unhappy with their display in Melbourne last week and will be determined to make amends on Sunday at the SCG.

“We were pretty disappointed,” Grundy said.

“We pride ourselves on playing consistently week-in, week-out and that’s something that dropped away on the weekend.

“We’re going to turn that around this weekend and we want to get our hardness back and our contested ball.

“Out here as well on the SCG it would be good to come back with a really strong performance and come away with a win.”