NORTH Melbourne defender Luke Delaney could complete one of the toughest AFL initiations ever this Saturday.

The 21-year-old rookie was elevated from North's rookie list last week and was immediately assigned one of football's most daunting tasks, manning Brisbane Lions skipper Jonathan Brown at the Gabba.

And when North takes on the Sydney Swans at Etihad Stadium this Saturday, Delaney could spend time on Adam Goodes when the Swans co-captain plays forward.

But Delaney performed admirably on Brown in his debut game and is excited rather than daunted by the prospect of playing on Goodes.

"I'll play deep against the Swans, so if Goodes is there, that's who I'll play on," Delaney said.

"I was rookie-listed here to play a key back role, so you've got to take the big boys down forward, whether it's Jonathan Brown or Adam Goodes."

Delaney said playing on Brown had been the biggest learning experience of his football career to date.

Although he had played on AFL-listed forwards like Geelong's James Podsiadly in the VFL, Delaney said Brown's intensity around the ball was "a notch up" from anyone he had played on.

But Delaney is obviously a fast learner. He kept Brown goalless in the first half last Saturday night and, although the two-time All Australian finished with four goals in his comeback game from multiple facial fractures, two of those goals came after Delaney's teammates Scott McMahon and Scott Thompson gave away 50m penalties.

Most impressively, Delaney held his own in one-on-one contests with Brown.

Like most players, Delaney was outbustled by Brown in some marking contests, but he outmarked Brown on other occasions and his spoiling had a touch of Mick Martyn's manic ferocity.

Obviously, Brown is just as dangerous when the ball hits the ground but, again, Delaney held his own in these contests. In one first-quarter duel, the pair ran at a loose ball on the wing, when, with deft use of his hip, Delaney bumped Brown off the ball and took off.

Although North coach Brad Scott described Delaney's game on Brown as "terrific", Delaney said he was reasonably happy with his performance, deflecting credit to his teammates who drifted back into Brown's space to lend him a hand.

Delaney spoke with afl.com.au at Aegis Park on Wednesday and we got the sense his head was still spinning at the speed with which he'd gone from playing in the VFL to manning some of the best key forwards in the game.

It was hardly surprising. Delaney only got his opportunity when fellow key defender Nathan Grima broke his finger at training the Tuesday before the Lions game.

But as quickly as his subsequent senior promotion occurred, Delaney's journey into the AFL has been long and injury-plagued.

He was limited to a handful of games in his first two TAC Cup seasons with the Geelong Falcons, but played a third season as a 19-year-old in 2008 when he finally enjoyed a better run with injury.

Delaney's performances that year - which included a strong defensive job late in the season on the Sandringham Dragons' No. 1 and No. 8 picks in the 2008 NAB AFL Draft, Jack Watts and Tyrone Vickery - convinced the Kangaroos to take Delaney with pick No. 25 in that year's NAB AFL Rookie Draft.

However, Delaney's injury woes returned in his first two years at North Melbourne. A shoulder reconstruction cut short his first season, while he missed seven weeks with a broken wrist last year.

Naturally, Delaney had some doubts during those times whether he'd get his chance at AFL level.

"Those thoughts do go through your head at times, you get down in the dumps a little bit," Delaney said.

"But North's a great club to be around. You've got the resources here to get you going."

Delaney's injuries couldn't hide his impressive development as a defender. He returned in the second half of last season to play a key part in North Ballarat's third consecutive VFL premiership, and his VFL form this year had been so good Scott recently rated him the club's best-performed key defender in 2010.

For Delaney, there has been one downside to finally getting his chance at senior level - it has come at the expense of Grima.

Not that long ago, the Kangaroos had a dearth of key defenders, but in Grima, Delaney, Robbie Tarrant, Scott Thompson and Delaney's younger brother Cameron, their stocks suddenly run deep.

"At the minute, we've got a few boys who are playing that key role down back, so it keeps everyone in good form," Delaney says.

Cameron Delaney, 18, was drafted by North with pick No. 69 in last year's NAB AFL Draft. Delaney has enjoyed having his younger brother at Aegis Park and playing alongside him at North Ballarat earlier this year, but says before his elevation there was one downside.

"I copped a bit of flak from a few boys here and some of the boys back home that my little brother was a senior player and I was a rookie," he says, laughing.

Given his form this year, it's flak Delaney won't have to put with again.

Nick Bowen covers North Melbourne news for afl.com.au. Follow him on Twitter: @NickBowen71.