SYDNEY Swan Heath Grundy showed in 2010 he had blossomed into one of the AFL's better key defenders.

Grundy, who turns 25 on Thursday, has continued that form this season, and was rated by many as best on ground in the Swans' stoic one-point victory over North Melbourne last Saturday.

After that game, Leigh Matthews added his voice to the growing chorus of belief in Grundy's ability to match it with some of the game's best forwards.

Grundy is part of a miserly Swans defensive unit that includes Tadhg Kennelly, Marty Mattner, Nick Malceski and Ted Richards.

First-year defender Alex Johnson is also establishing himself down back, while Rhyce Shaw and Nick Smith are filling tagging roles with aplomb.

One area the Swans are struggling, however, is in attack. They have scored over 100 points just three times in nine games as they introduce a new forward line.

Full-forward Daniel Bradshaw has been sidelined all season, while impressive youngsters Sam Reid and Lewis Johnston are just beginning their AFL careers.

Grundy also began his career as a forward, but doesn't see himself as a solution.

"I can't remember it, it's been a while," he said with a grin of his time in the forward line.

"They were pretty short days. I'm happy down back at the moment.

"I actually played a bit of both as a junior, but coming up here I suppose they saw me as playing forward so I did that for about three or four years.

"That's where I was always practising to play, but then they threw me down back and I've been down there since.

"'Roosy' (former coach Paul Roos) just threw me down there and gave me some different roles and I seemed to adjust to them quite well, being able to run off as well as defend.

"So I guess over a period of time I played a lot more down there and found my feet."

Named the Swans' most improved player in 2009, Grundy's defensive education reached another level in 2010, when injuries to Craig Bolton and Lewis Roberts-Thomson increased his opportunities.

He finished fifth in the club's Bob Skilton Medal count last year, ahead of Adam Goodes and fellow All Australians Brett Kirk and Ryan O'Keefe.

Grundy has terrific closing speed and backs himself in marking contests, two traits that will be vital when he lines up on Brisbane Lions captain Jonathan Brown at the Gabba this Saturday.

The Lions have recorded back-to-back wins since Brown returned from injury against North Melbourne in round nine.

"They played well down in Adelaide and they're back in a bit of form, which is good for them. They're always a challenge up there in Brisbane," Grundy said.

"(Brown's) a good player and obviously they're a different, better side with him back in and he makes a big difference.

"If we can shut him out it'll make a huge difference to us winning the game.

"He gives them more of a focal point and straightens them up a bit through half-forward and if he gets off the chain he normally kicks a few.

"I just try to play my game and if the other defenders can come over and help and everyone's doing their job, it makes it a lot easier."

Recruited from Norwood in South Australia in 2005, Grundy has been a key part of the club's gradual rebuilding process since their premiership victory that year.

Now an automatic selection each week, Grundy likes what he sees around him at the club.

"We've got a lot of depth in our list at the moment and there's a lot of guys in the twos pushing hard for selection as well, which puts pressure on the senior guys," he said.

"We've got some good young guys coming through getting some games.

"Lewis Johnston showed on the weekend he can play at the top level.

"Alex Johnson's been good. He's still young, but he's been playing on some pretty good players. It's pretty exciting for the future.

"Obviously we've always got room for improvement and there's no doubt we can play a lot better than we have and we've got better footy to come.

"We're still trying to improve. It's halfway through the season now and hopefully we can build up and get closer to the finals."