DYNAMIC St Kilda forward Mav Weller concedes he struggled mentally with an ongoing ankle injury last year but has stripped weight and is ready to return to his best form in 2018.

Weller suffered a right ankle sprain at training ahead of the Saints' round seven win against Greater Western Sydney and missed just a week.

"It was a recurring thing in the end and it probably should have only been a three or four-week injury," Weller said on Thursday.

He had troubles with it throughout the season and was dropped for rounds 16-18. 

The 26-year-old was a member of the leadership group and said he should have coped better. 

"It was frustrating. It definitely played on my mind. I probably didn't deal with it the best each week," Weller said. 

"Ideally, I probably should have had a bit of time off. They're things that I can't control and I just wanted to do my bit for the team. It didn't play out the way I wanted it to but it's all good, I'm fit and healthy now."

It meant he could not do aerobic training and Weller admitted he "ballooned out".

Since then, the Tasmanian has lost eight kilograms over the pre-season and hopes being fitter will help him reclaim a spot in the leadership group in 2019.

He was not voted into this season's contingent but said he will continue to lead. 

"We've trimmed our leadership group, so it's a little bit easier to gather opinions and execute. We found last year grabbing eight or nine blokes and dragging them all into one room and getting guys throughout the day was pretty hard," Weller said. 

"I'm still a massive part of that and the leadership around the club." 

St Kilda is down to a five-man leadership group this year, with David Armitage, Josh Bruce and Weller not making the cut.

The club trained at Trevor Barker Beach Oval for a final run-through of AFLX ahead of its tournament on Friday night at Etihad Stadium. 

Everything you need to know about AFLX

"We're taking it pretty light-heartedly," Weller said. 

"We're really looking forward to just going out there and having a bit of fun. 

"It's a bit of a mental freshen up. You can challenge yourself in different skills and different rules of the game."

Reigning best and fairest Seb Ross will captain the 20-man squad while fellow midfielder Luke Dunstan will skipper the side Ross is not part of.

The Saints will field completely different teams for their two pool games against Essendon and Hawthorn.

See the AFLX fixture and get your tickets here 

Draftee Hunter Clark sported bandaging on his left calf after copping a knock recently but trained fully and will play on Friday. 

"The boys are all pretty keen to play it. We've been using it as a conditioning drill during the pre-season, so I think the boys have all put their best foot forward and keen to go out there to have some fun," Weller said. 

"Who wouldn't want to go out there? We're going to be at Etihad, there's probably going to be a fair crowd and fireworks and all the rest and it should be a bit of fun."