After the late-season injury to James Gwilt and the departure of Zac Dawson, the Saints' tall defensive stocks are looking stretched and the 191cm Dempster knows he is more than likely to find himself alongside some of the competition's bigger bodied forwards.
"I think the opportunity is there. We don't really have one big player to play the role," Dempster said on Thursday.
"We've got a spread of blokes around the 190cm mark so there's a bit of responsibility on everyone's shoulders to play against the big key forwards."
Dempster finished third in the Saints' club best and fairest last year, firmly establishing himself as a crucial part of the Saints' back half.
But with Scott Watters taking over the reigns from Ross Lyon at the Saints, the 28-year-old is well aware that the deeds of the past count for little.
"It's a new coach so you want to put your hand up and show him what you've got to offer," he said.
"We haven't really spoken specifics so I'm not really sure what my role in the team will be. Like I said I put my hand up and will do my best."
Dempster's forte - defence - has been a constant focus for the Saints in Watters' first pre-season at the club. But he said there will be improvement both in the back line and the forward half.
"We've been working on a few areas and hopefully this will come out in the pre-season games," he said.
"Like most clubs, everyone wants to get better at their defence and that defensive press, everyone's going to be working on that this year and probably in the past our attack hasn't been great so that's been something we've also been working on.
"Both ends of the ground we've been working pretty hard on and hopefully it comes out in the games."
The Saints take on Geelong and the Sydney Swans in Friday night's clash at Etihad Stadium. The matches will be the first time Lenny Hayes has played since injuring his knee early last season.
Dempster said his 32-year-old teammate was as bubbly as ever ahead of his return.
"He's like a young kid again," Dempster said.
"He's come back really well, his rehab has been faultless and he's been training full on since Christmas so he can't wait to get out there and we can't wait to play with him again."
Luke Holmesby covers St Kilda news for afl.com.au. Follow him on twitter - @AFL_Luke
