THE LONG-TERM Achilles injury to Adelaide captain Nathan van Berlo leaves a significant hole in the side's midfield and Brodie Smith wants to fill it.

The 22-year-old blitzed the club's time trial at the first training session after Christmas and, on the eve of the NAB Challenge, is a frontrunner to win more onball responsibility.

Having played on the half-back line during his three seasons at West Lakes, Smith told AFL.com.au he had always wanted to be a midfielder.

As unlucky as the skipper's ruptured Achilles was for both van Berlo and the club, it has created an opportunity for others.

"A couple of midfielders are gone now and with VB, such an unfortunate event, but I guess that does open up a spot there," Smith said.

"There are a lot of guys fighting for it, so I don't know whether I can get a chance there or if I'll stay across the half-back line – it's up to the coaches.

"I've played half-back the last couple of years but when I got drafted to the club I came as a midfielder so I've always been pushing to try and have a crack [there].

"Every pre-season I've done a little bit more and learnt a little bit more about the midfield but I'll play wherever I'm needed."

Smith's pre-season form is certainly offering him every chance to make the onball move.

In further evidence of Adelaide's changed training direction ahead of the 2014 season, he's lighter than this time last year and he's running faster times on the track.

So improved is Smith's running that he finished second to perennial pace-setter van Berlo at the club's first time trial back from its Christmas break.

"There's been a bit more focus on fitness this year with the new interchange rule, so my weight's a little bit down compared to this time last year," he said.

"But I'm comfortable with what my weight is – I feel fit.

"Now I am just a little bit lighter it helps with the running; you can run a bit better in time trials."

But he's not alone in the fight to replace van Berlo.

Mitch Grigg, 21, and Sam Kerridge, 20, both enjoyed solid seasons last year, while Smith talked up the training form of 18-year-old draftee Matt Crouch.

Then of course there's Matt's 20-year-old brother Brad - a star in the making.

"Griggy, Sam Kerridge, young Crouchy's come in and trained really well and obviously his brother's going to be there, so there's a lot of us young guys trying to get into a midfield that's already got (Rory) Sloane, (Richard) Douglas, (Patrick) Dangerfield and (Scott) Thompson," he said.

"It's looking like a really strong midfield and there's going to be a lot of guys trying to grab those last couple of spots.

"The competition at the moment is very high."

Smith said he had been working hard this summer with club midfield coach Scott Camporeale on the finer points of playing onball - body work and positioning.

Dual club champion Scott Thompson has also passed on his knowledge, leaving Smith set to join Dangerfield, Sloane and Douglas in the club's engine room. 

"Just trying to learn the craft of being a midfielder is the main thing for me especially this year, I've done a lot of work with Campo, and Scotty Thompson's been really good," he said.

"I just have to keep chipping away at that and try and have it down pat by the time the season starts to see if I can have a crack."

Twitter: @AFL_Harry http://afl.to/harrythring