WHEN young defender Jared Petrenko was first thrown into Adelaide's attack during a NAB Cup game against Geelong last pre-season, he admittedly had no idea what he was doing.

Petrenko struggled to drop his defence-first instincts and felt as though he was simply getting in the way of his more experienced teammates.

But when injury began to rattle the Crows' forward line in January, Petrenko realised his best chance of adding to his nine-game tally was going to come in the unfamiliar territory.

"In defence I'm competing with guys like Graham Johncock, Andrew McLeod and Simon Goodwin and it's pretty hard to push guys like that out," Petrenko said.

"All the injuries are coming up forward and in the midfield, so that's where I'm going to have to play if I want to get in the side. It's unfortunate for those guys that are injured, but it opens up a lot of windows for young guys like myself."

Petrenko set about adjusting his natural game to better suit a role in the forward line.

The 20-year-old also had to change his mindset from hesitant to selfish and goal-hungry.

"Last year when I went up forward the coaches were really happy with the defensive side of my game, but I didn't really go for the ball that much because I thought I was just getting in the way," Petrenko said.

"This year I've put more of a focus on being confident to go for the ball and knowing that I'm out there to win the ball as much as I am for my defensive pressure."

Petrenko and second-year utility Shaun McKernan were the only two players to earn praise from coach Neil Craig following the side's disappointing performance against Port Adelaide in round one of the NAB Cup.

Craig lauded the pair's competitive spirit and has since entrusted Petrenko with setting the standard at training in the areas of intensity and contested ball.

"That's just how I play my footy. In your first couple of years at a club it's hard to get into the team and when you get an opportunity you've got to go as hard as you can for the whole time," Petrenko said.

"It might be easier for the older blokes to float through if they're having a bad game because it's harder for them to get dropped, but blokes like myself don't get too many opportunities, so when you get them you've got to go for it."

Petrenko played the opening eight games of 2009 - his first season on Adelaide's senior list - but managed just one after round nine despite being named an emergency seven times.

"I worked really hard to get to where I was at the start of last year and I think I got a little bit too comfortable just playing week-in and week-out," he said.

"This year I'm going to put a greater emphasis on pushing myself for the whole year and staying in the team. I won't let that (complacency) happen again and I'm ready to make more of an impact."

Petrenko was one of the Crows' best players in the loss to Collingwood last weekend and assistant coach David Noble said the Woodville-West Torrens junior had matured since arriving at the club at the end of 2007.

"We've really seen Jared grow with his capacity to use his voice more and instruct players out on the ground," Noble said.

"I think he's found some belief. He's been able to train consistently and prove probably more to himself than anyone that he is capable of being able to sustain a position in our side at AFL level."