TYSON Goldsack has become the third Collingwood youngster this season to earn a nomination for the NAB AFL Rising Star, with the promising defender claiming the honours for round 21.

Goldsack joins Scott Pendlebury and Martin Clarke as the Pies' eligible players for this season's prize, after an impressive performance opposite Sydney spearhead Michael O'Loughlin on Saturday night.

"I felt a lot more comfortable that game, because I had last week off and had a rest week," Goldsack told afl.com.au, after learning of his nomination.

"Going into the game, I felt really good and a few of the boys after the game were congratulating me. I felt good, and I was getting a fair bit of the ball as well."

Goldsack was taken with pick no.63 in the 2006 NAB AFL Draft, after spending an extra season with TAC Cup side Gippsland Power as a 19-year-old.

He was one of two players permitted by each side to remain in the competition outside the normal age restrictions, owing to the fact he had only played a handful of TAC Cup games and had been in the under-18 system for just six months.

The 20-year-old was not drafted in the first year he became eligible, and instead had to wait another 12 months for the Pies to add him to their list.

Since coming to the club, Goldsack has been pushed into defence after spending the majority of his younger days as a forward/midfielder.

"It's a bit nerve-racking at the start when I've been told who I'm about to play on, but it's all just experience," he said, of the shift down back.

"The more jobs I get to do, the better I'll be in the end. It's been tough but it's been good at the same time."

Having spent time on forwards such as Lance Franklin, Russell Robertson, Steve Johnson and O'Loughlin, Goldsack has been given a baptism of fire in his debut season and first year playing as a key defender.

It's not a challenge he's prepared to shy away from – instead, he looks at each week as another chance to gain experience.

"There's a fair bit of trust there [from the coaching staff], but with the injuries we've had, there's probably been no other choice, really," he said.

"It's been a good opportunity. With the injuries we've had, for me to come in and then stay in the team was probably my main aim.

"Now, I'm just happy to be in the team."

He said he has relished the change in pace.

"I think they had their sights set on me to play in the midfield and down back when I first got drafted. In the VFL, I played in the backline because we had a few injuries there as well," he said.

"I strung together a few good games in the VFL, which is probably where I got my chance because we had Jimmy Clement and a couple of other boys out.

"It's where the opening was, and they've tried to make my spot there."

Goldsack kicked two bags of five goals in the TAC Cup last year, and while he's enjoying life on the other side as a defender, he admitted he does miss the exhilaration of booting a big goal.

"I live with a couple of players and we watch ‘The Winners’ and a couple of other shows, and they only show goals," he laughed.

"It's usually me that gets the goals kicked on them, and you can just see me with my head down. But I don't mind. As long as the other guys are kicking goals, that's ok."

So far, he's played 13 games this season since making his debut in round eight against the Bulldogs, and has missed only round 20 when he was given a week off.

He has averaged nearly 13 disposals a game, with his best coming against the Swans on Saturday night – 25 possessions, eight marks and four tackles.

The other nominees for the 2007 NAB AFL Rising Star are: Paddy Ryder (Essendon), Cameron Wood (Brisbane Lions), Tom Hawkins (Geelong), Scott Pendlebury (Collingwood), Joel Selwood (Geelong), Ricky Petterd (Melbourne), Jess Smith (Kangaroos), Shaun Higgins (Western Bulldogs), Mitch Clark (Brisbane Lions), Bryce Gibbs (Carlton), Shannon Hurn (West Coast), Robbie Gray (Port Adelaide), Marty Clarke (Collingwood), Scott McMahon (Kangaroos), Justin Westhoff (Port Adelaide), Sam Gilbert (St Kilda), Nathan Jones (Melbourne), Tom Williams (Western Bulldogs),  Travis Boak (Port Adelaide) and Mark LeCras (West Coast).