All Australian lock Tom Jonas concedes he must battle to “rein in’ aggressive instinct.

All Australian lock Tom Jonas’ double-barrelled battle to “rein in’ his aggressive instinct and ensure Port Adelaide negotiates Saturday’s banana-skin clash against Carlton.

All Australian candidate Tom Jonas has revealed a double-barrelled battle to “rein in’ his aggressive instinct and ensure Port Adelaide negotiates Saturday’s clash against Carlton.

Jeremy Cameron’s ban for steamrolling Brisbane’s Harris Andrews and Jonas’ fair but risky bump on Melbourne’s Tom McDonald last Friday was a timely reminder to “keep his nose clean” after being suspended for Port’s losing 2017 elimination final.

The immediate concern for Port’s leadership group - which includes 115-game star Jonas - is underpinning its hard earned consistency against bogey side Carlton at the MCG.

“Those sort of games haven’t been our strength for a little while now and if you look at our record against Carlton the last couple of years it is definitely a danger game,” said Jonas, with the bottom-ranked Blues winning two of their last three matches against Port.

A fourth-straight win against the unit that derailed Port’s 2015 finals assault at the MCG will showcase professionalism needed to reach a top-four berth.

“We have had a bit of focus in making sure we don’t get complacent, still do what has worked the last three weeks,” Jonas told The Advertiser.

“I think it will be telling for us about how much we have matured.”

Robbie Gray is Port’s bona fide superstar but Jonas, 27, is irreplaceable as the rock for a young Port defence.

A two-game suspension for a bump on Western Bulldogs’ Luke Dahlhaus at Ballarat in round 22 last season meant Jonas sat out the extra time elimination final loss to West Coast. Jonas wants to make amends.

“I would say I certainly haven’t mastered my aggression. It was nice to get off a good bump but at the same time I was lucky Tom is 6’5,” said Jonas who knocked the impetus of McDonald and Melbourne in the final term at Adelaide Oval.

“If it had been a smaller opponent I am not sure what the result would have been.

“I definitely still tread the line and get nervous but instinct does take over and it is hard to rein it in.

“It feels like a fair while ago but prior to the Ballarat game I thought ‘it had been while since I got myself in trouble’. I am just hoping to keep my nose clean for the rest of the year.”

Jonas, who copped a six-game ban for a collision with West Coast’s Andrew Gaff in 2016, has learnt the hard way how team fortunes can change in split second decisions that only players appreciate.

“We definitely underestimate it. We see examples each week, the game is played so fast, we are such big strong bodies that it doesn’t take much for injuries to be caused,” said Jonas. “When you are watching it in slow motion it is definitely a different kettle of fish.”

Jonas is rated as one “of the great backs in the competition” by coach Ken Hinkley having shut down an all star cast including Patrick Dangerfield, Josh Kennedy, Eddie Betts, Jesse Hogan, Ben Brown, Josh Caddy and Joe Daniher this season.

All Australian selection beckons but it’s low on Jonas’ priorities.

“It would be a great honour to be included but my main focus is being involved in a really strong finals campaign. We have a chance over the next month or so to set ourselves up for that,” he said.