BRODIE Grundy came to football late.

He played basketball for most of his youth. He was never obsessed by footy, and it hasn't always been his dream to play it at the top level.

But it is a path he seems set to take.

Grundy, a shaggy-haired 200cm ruckman from Unley in South Australia, is considered one of the premier big men of this year's NAB AFL Draft.

But what makes Grundy perhaps most interesting is that he is also one of the year's most raw prospects. He's big, strong and powerful.

Grundy's progression began when he played with South Australia's under-16 state team in 2010. He entered the championships on the outskirts of the best 22, and even by the last game was one of the final players picked.

But the coaches saw a competitive streak in Grundy they liked. Nobody, though, was quite sure Grundy would perform as well as he has.

In 2011 he was inducted into the AIS-AFL Academy squad (a feat he repeated in 2012). He played for Sturt in the SANFL and shouldered South Australia's ruck division in the NAB AFL Under-18 Championships.

"He made a massive improvement in a short period of time," says Brenton Phillips, coach of South Australia.

Grundy has all the essentials in place as a ruckman. But it is his extra features which have recruiters most excited.

At one stage in the AIS-AFL Academy's loss to the Box Hill Hawks last month, Grundy followed up his hit-out by winning the ball at a stoppage, busting through a pack and having a running shot at goal.

He knows the game has changed and requires ruckmen to make an impact in several ways. He knows the type of player he wants to be.

"I like the way Nic Naitanui plays, he's just so athletic and does some incredible things," Grundy told AFL.com.au.

"But I really like the way Paddy Ryder goes about his footy. He's pretty versatile, can move around the ground really well and can go up forward and take a grab, too."

There is a long way to go before Grundy reaches that level. Playing at senior level last year sped up his learning process, and he's taken some of those lessons into this year.

"Everyone and everything is so quick," Grundy says of the SANFL.

"Everyone is bigger and stronger and more aggressive, and sometimes I was playing against guys who were more than 10 years older than me. So I've worked hard on my physicality to be ready for it."

Grundy might be being modest about his strength. Matthew Lloyd, the Essendon champion and AIS-AFL assistant coach, ranks Grundy as strong as any player his age.

At some academy training sessions, Grundy and Joe Daniher, a forward/ruckman destined for Essendon at the end of the year under the father-son rule, go head-to-head in marking and ruck duels. Daniher has to play off Grundy and use his leap, while Grundy tries to engage Daniher physically and beat him by using his strength.

"They're great battles to watch," Lloyd said. "It's when Brodie is at his best."

It's where his instinct takes over. He sees the ball and scraps, pushes and nudges his way to the front. But there are other times where his limited football background means he requires direction. Or, as his Sturt coach Seamus Maloney says, "He can need a bit of prodding sometimes."

Over pre-season at Sturt the club was running 400m trials. In the first one, Grundy was in the middle of the pack before falling behind with the other key position players.

At the next break, Maloney told Grundy just because he as a ruckman it didn't mean he had to fall in line. If he was good enough, if he wanted to win the trial, he could. Grundy won the next two.

At half-time in South Australia's match with Western Australia in last year's championships, Phillips (forcefully) told Grundy he needed to lift his game. Grundy sat up and took notice, and then went out to be best on ground in the second half.

"He wasn't putting a stamp on the game," Phillips recalls. "But he definitely did in the second half. He branded it."

Grundy is aware of where his footy sits and what he needs to do. He's regularly asking about when he should push forward or run back to help in defence.

He's been encouraged to go to as many AFL games as he can this year to watch ruckmen, and see how the best do things on game-day. He's also got an eye on winning more disposals and becoming a more damaging, complete player.

At his rate of development, everyone thinks he'll get there.

"He's still learning about footy, and understanding what it takes," Lloyd says. "But he's improving every time you see him, and that's what's exciting."

Callum Twomey is a reporter for AFL Media. Follow him on Twitter at @AFL_CalTwomey.