Defender Tim Mohr says improved professionalism has been the catalyst behind his emergence as one of Greater Western Sydney's more important players.

Jeremy Cameron, Callan Ward, Shane Mumford and youngsters like Adam Treloar, Dylan Shiel and Devon Smith generate much of the publicity at the GIANTS, but Mohr can be just as influential as any of them.

A key defender who didn't take up the sport until the age of 14, Mohr has steadily improved since joining GWS as a mature-age recruit ahead of the club's debut season of 2012.

For a side lacking tall defensive reinforcements, the 196cm, 103kg Mohr's presence is badly needed, although he admits it took him some time to appreciate what's required at the top level.

"It's been good. It gets easier and easier every year for me," Mohr told AFL.com.au on his time as a GIANT.

"First year, I was 22, 23 years old, coming into an AFL system, a bit older, not knowing anyone and a bit as a raw footballer.

"I wasn't all that professional to be honest, but my last two years my professionalism has got heaps better and that's helped a lot."

More interested in skateboarding than football growing up in Launceston, Mohr started taking the sport more seriously in his late teens, although he says he was "riddled with injuries from 18 to 22".

He started doing weights to build up his body and it led to a best and fairest-winning season with Casey in the VFL prior to being picked up by the GIANTS.

Making 13 appearances as a rookie, he then played all 22 games in 2013, adding starch to a fledgling backline that had to endure Chad Cornes' forced retirement and Phil Davis' extended absence with a back injury.

Foot and knee issues kept him out of the opening nine games of this year, but he has played the past three games in the seniors and will have another big job when GWS takes on Carlton at Spotless Stadium on Sunday.

"He's one of those late bloomers," coach Leon Cameron said.

"Coming from Tasmania, then getting picked up by the GIANTS as a 22-year-old, he's matured year by year.

"He really understands now what he has to do to play regular AFL football and hopefully can continue this great form for the rest of the season."

Mohr says it was tough trying to hold down a key post in a backline that regularly had big scores kicked against it during the club's early days.

But he believes he and Davis, who has just returned from his long layoff with a serious kidney injury, are improving every week.

Tom Hawkins and Lance Franklin are two of the key forwards Mohr has been charged with marking during his 38 games, while he nominated West Coast's Josh Kennedy as his toughest opponent to date.

The 25-year-old, who recently signed a two-year contract extension, feels the GIANTS have turned the corner after some lean recent form.

With many of the club's young talent off contract at the end of 2015, Mohr also believes the vast majority will pen new deals.

"I'm confident most of them will stick around," he said.

"We're all pretty close and it's hard to move to a new club and have to make all new friendship groups.

"I love playing up here with all my mates, the club gave me an opportunity, and I just want to repay them the best I can."