NUGGET, Mongrel, Pig Dog: Adelaide’s Aidan Riley has been known by a number of nicknames that, at first, sound more like insults than terms of endearment.

Ask around though and the true meaning of Riley's other names and the respect they carry becomes abundantly clear.

Despite his 182cm frame, the 21-year-old Crow is one of the toughest and most physically imposing players on Adelaide's list.

Just ask his teammate, reigning NAB AFL Rising Star winner Daniel Talia, who told AFL.com.au 'Pig Dog' was a nickname Riley should be proud of … most of the time.

"He's not the best looking type of bloke, so I'd have to say that's how he got it," Talia joked.

"No, look, he's one of the hardest blokes going around, he tackles like crazy and in all the wrestling and boxing we do he's just fearless. I think a few of the boys are scared of him.

"He gets in and under the packs and takes guys out with tackles, so he's highly-regarded in that contested ball area."

Riley's love for the contest and the physical aspect of sport was so intense as a kid that his father Peter stopped watching him play rugby league in the Illawarra region of New South Wales.

Riley was only young, and his father couldn't handle watching his first-born take continuous hits from boys much bigger than he was.

Ironically, the brutality of rugby league saw Riley's parents gently push him towards AFL, unaware that he would master the crash and tumble side to the game.

"He used to drop me off for my primary school games and go and get a coffee somewhere; he couldn't watch it because it was too brutal – just hit-up after hit-up," Riley said.

"I'm not really sure whether playing rugby league has anything to do with the way I play these days, [but] my dad would probably say I was a pretty physical kind of kid.

"One of the main reasons I chose to pursue AFL was because of the physicality of the contact involved in it.

"I'm not the biggest guy going around. I just really enjoy that contest, putting yourself against someone else and trying to beat them."

Riley insists his dad has come around to his style of play and even commends him after a particularly bone-crunching hit, whether it's playing for Adelaide in the AFL or Sturt in the SANFL.

"He loves it now, he knows I can take care of myself," Riley said.

"Every time I come off and he's seen the game, he'll say he liked this hit or that. He enjoys it now, which is a bit different to when I was younger."

Riley’s fearless style of play can come at a cost, and he is no stranger to the dangers of concussion.

With the long-term effect of head-knocks still relatively unknown, the young midfielder admitted to concern about the after-effects of concussions, not only for himself, but for any sportsperson.

Riley said he had suffered four "serious" concussions in his sporting career, but insisted he felt safe in the hands of Adelaide's club doctors and their conservative approach to recovery after a significant knock.

"I had a pretty severe one in the under-18 championships against the Northern Territory where I had to get taken to hospital and I had another one in the under-15 championships," he said.

"My dad's always been massive on making sure your well-being's put first.

"Our doctors do a very good job with that. I suppose Kurt (Tippett) was a good example last year, who was out for a number of weeks because he wasn't completely right.

"It's what you've got to do now, the medicos do a great job to make sure we're 100 per cent before we're back out there."

Approaching the end of what's been a bumper pre-season, Riley is on the cusp of round one selection.

Prior to last Saturday's disappointing four-disposal effort against Geelong he was flying and drawing admiration from coach Brenton Sanderson.

Sanderson maintained Riley was still right in the hunt to add to his 10 AFL games when the Crows' season opens against Essendon on March 22, but with the Adelaide midfield boasting such class as Scott Thompson, Patrick Dangerfield, Rory Sloane, Nathan van Berlo, Bernie Vince and Matthew Wright, breaking in will be difficult.

Riley will get an opportunity at some point in 2013, but the trick to cementing a spot in the line up, he believes, was to make sure his form made him undroppable.

He also conceded he had to improve his outside game.

Riley’s inside game has always been his strength, but until his work away from the contest reached an elite level, he admitted it would be tough to force one of Adelaide's stars out of the line-up.

"You've to keep doing what you do well, which is my inside clearance work, but then you have to add to that and show the coaches something a bit different that will get me a spot in the team," he said.

"A constant theme since I've been at the club has been that my inside stuff's been good, but I need to work on the outside stuff.

"When I can add that to my game consistently, that's when I'll see the big improvement, but I think it's at a level now where I can compete in the AFL."

Aidan Riley is a midfielder in AFL Fantasy. He averaged 55.75 points in 2012. Register your team at our AFL Fantasy Hub.

Harry Thring is a reporter for AFL.com.au. Follow him on Twitter: @AFL_Harry.