IT SEEMS bizarre to think that Daniel Pratt still doesn't feel assured of a berth in the Kangaroos' starting line-up from week to week.

The aggressive defender has filled with aplomb the role of clamping down on the opposition's small crumbing forward since early last season; no small matter given this has been problem area for the Roos in recent years.

And yet, fresh from keeping Geelong danger man Gary Ablett to just 10 possessions and one goal last weekend, Pratt admits he sometimes feels he is just one week away from dropping back to the VFL.

It's not that he doesn't think he is doing his job; it's more that he knows one undisciplined slip-up will see him put into the coach's bad books. It's a thought that crossed his mind after a goal square altercation with Ablett resulted in a 50m penalty to Geelong in the Roos' rousing win at Skilled Stadium at the weekend.

"There are obviously boundaries that I have to stay inside regarding the physical side of my game," Pratt said. "Sometimes if you go over the top I'm sure that puts your position in doubt in the coach's mind.

"I know I probably caught Gary a little high at the weekend and Dean had a little bit of a chat about that to me.

"But as long as I play within the boundaries we've set, I think I can keep my spot in the side. I just have to make sure I keep things like that under control."

No doubt his teammates will be hoping he can keep his reckless tendencies in check, particularly those who go into battle with him inside the Kangaroos' back half each week. The Roos have developed a tight defensive unit across the early part of the season, and Pratt is a key member of that team within a team.

"We've got a good group of young to middle-age defenders, with Drew Petrie turning 25 later this year, and me, Gibbo and Mick Firrito all around 23 or 24. So we have four blokes there who are hopefully going to be at the club together for the next five or six years.

"Along with Shannon Watt, if we can keep that core group together and blokes like Archie or one or two of the young blokes can come in and help us out every now and then, we can keep things nice and tight. Teams might then start worrying about us when they play us."

Pratt said that while keeping the goal count down was an obvious aim for him and his defensive comrades, part of the team's new attacking mindset meant that the Roos' coaching panel was keen to do away with the tactic of running a loose man in defence for large parts of the game.

To that end, he said there has been a major emphasis on filling the backline with players capable of winning the contested ball. It had been a key focus in the off-season and continues to be at the forefront of his teammates' minds as they prepare for battle each week.

"When we got together at the start of the year we spoke about wanting to be one of the more physical backlines. With a more attacking focus we wanted to be able to play more accountable, contested footy in the backline.

"If that's how you want to play you have to be able to beat your man in those important one-on-one contests. We think we've got blokes down there that can do that.

"It's something we can all think about, to win those 50/50 contests, and that's what we can hopefully get through the whole club, from the experienced blokes right down to the young guys coming through. I reckon that ability to beat your man is something that sets you up for senior footy."

The views in this story are those of the author and not necessarily those of the club.