A FITTER Paddy McCartin believes St Kilda can challenge for finals this season and says the positive direction of the club made his decision to re-sign for two more years a "no-brainer".

The former No.1 draft pick has put pen to paper on a new deal tying him to the Saints until at least the end of 2018, when he expects St Kilda to be in the finals mix.

But McCartin is quietly confident the young Saints' strong pre-season to date will see them improve from last year's six wins and push up from 14th spot on the ladder.

"On and off last year we were really good, we [showed] really good pressure and played really well as a team at times, but then there were times we let ourselves down," McCartin said.

"Hopefully, we can turn that around this year and turn that into more consistent performances.

"I'd like to think (we can play finals this year). Every team goes into the season hoping they will play finals and to get the most out of themselves, so we're definitely wanting to go as far as we can this year.

"I think the way we've been training lately, we can put in a pretty good effort this year."

McCartin managed six games in his first season, making his debut in round three as a last-minute replacement for Nick Riewoldt, before dropping back to the VFL to work on his craft.

The 19-year-old power forward returned late in the campaign and showed his potential taking nine marks and booting a goal in a win over Melbourne in round 17.

However, he still attracted criticism from pundits including Dermott Brereton, who said the young Saint needed to work hard at "physical aspects" of his game.

McCartin said he took constructive criticism on board and after completing about 85 per cent of pre-season training – more than double from last year - he had made some "pretty significant" improvements in his conditioning.

"I'm not a massive reader of all that kind of stuff, but it's Dermie's job to do that kind of thing – he's entitled to his opinion as everyone else is," McCartin said at St Kilda Sea Baths, where the Saints launched a new membership drive.

"You cop all that and that's just part of being an AFL player, you get criticism – whether that's constructive or not – from anywhere.

"As a first-year player as well you come in as a bit of a sponge and just try to absorb as much as you can, so I take constructive criticism wherever I can.

"Obviously, I want to try and play as much as I can and play consistent footy and hopefully with that the team gets some success. 

"It was a no-brainer really (to re-sign), the club looked after me a lot last year and showed a lot of faith in me and I'm really looking forward to the next couple of years."