AN UNCONVENTIONAL pre-season has helped Nick Riewoldt lose five kilograms and improve his running capacity even further, says St Kilda coach Alan Richardson.

Riewoldt has made a career out of running opposition defenders into the ground, and this weight loss should ensure the 33-year-old can maintain his form as he reaches the twilight of his career. 

The six-time best and fairest toured Ireland with the International Rules team before going to Texas where he stayed with his wife's family.

Riewoldt spent Christmas in the US and the extended break doesn't appear to have hindered his training at all.

"[Riewoldt's] running is incredibly strong at the minute. He had a different preparation," Richardson said.

"After the challenging year he had last year we gave him some time away.

"That's exciting for him whether he plays forward or in the midfield. The plan is for him to do a bit of both."

The Saints will field a significantly strengthened outfit against the Brisbane Lions this Sunday in Mackay. 

Riewoldt, David Armitage, Leigh Montagna and Sam Fisher will kick off their 2016 campaign, provided they get through training.

Armitage will be returning home to Mackay for the region's first ever AFL pre-season game. The 27-year-old finished second in St Kilda's best and fairest last year.

Paddy McCartin will miss against the Lions but should be fit for round one. The top draft pick in 2014 suffered a low-grade hamstring strain halfway through the first quarter in St Kilda's opening NAB Challenge game against North Melbourne.

"Paddy won't play. It's a hamstring, so the reality is that no matter how minor, 21 days for our footy club applies. That will be the minimum," Richardson said.

"At this stage, he'll be ready for selection by round one. That doesn't necessarily mean he'll play."

The 19-year-old played six games in his debut season. 

Forward Tim Membrey had a right shoulder reconstruction at the end of last year after and Richardson said he would return soon. 

"Tim will be pretty close to playing this week. We've got to assess today and Thursday," he said.

Ruckman Billy Longer also had shoulder surgery around the same time as Membrey and is fit, but is being kept out of the side by Jason Holmes and Tom Hickey.

"We were reasonably happy with what our rucks did. Depending on what happens with the guys in the team, that will determine how quickly Billy gets back in.

"His commitment to his recovery has been really positive." 

With the Saints set to play experienced squads for the final two NAB Challenge games, Richardson said draftee Brandon White was unlikely to play in the near future. 

Richardson also said the club was taking a long-term view with Collingwood recruit Nathan Freeman, with the 20-year-old highly unlikely to be ready for round one.