North Melbourne forward Paul Curtis will miss the next three games after unsuccessfully challenging his suspension at the AFL Tribunal.

Curtis was handed the sanction for a controversial dangerous tackle that drove Port Adelaide’s Josh Sinn’s head into the ground during the Roos’ loss at the Adelaide Oval, which left Sinn with a concussion.

The Roos argued Curtis’ conduct was not unreasonable or careless in attempting to overturn the ban, but also challenged Match Review Officer Michael Christian’s grading of the incident as ‘severe impact’, calling instead for a grading of ‘medium’ that would have downgraded the suspension to one week.

However, they were unsuccessful on both counts, with the Tribunal upholding the original suspension.

As a result, he will miss games against Essendon, Brisbane and Richmond unless the Kangaroos challenge the Tribunal’s verdict at the AFL Appeals Board.

The Kangaroos argued that Curtis fulfilled his duty of care to Sinn by dropping his weight to the ground while executing the tackle and holding him side-on, rather than forcing him straight down.

Curtis’ counsel Justin Graham said it was Sinn’s knees hitting the ground that caused his head to hit the turf, further adding that to tackle while pinning both arms, which the AFL argued Curtis shouldn’t have done, was ‘good practice’ and allowed under the laws of the game.

“A reasonable player would tackle in Curtis’ position and do so in a manner that tried to avoid the risk by using the technique Curtis did with his knees to the side and trying to halt momentum by dropping down,” Graham said.

The Roos compared the incident to Patrick Dangerfield’s tackle on Carlton’s Sam Walsh last year, for which the Geelong captain was initially suspended but was cleared of at the Tribunal.

The AFL argued Curtis’ tackle was unreasonable, and that he could have released one of Sinn’s arms to allow him to brace for contact, while also claiming he didn’t do enough to prevent the Power defender’s head hitting the ground.

This argument is what swayed the Tribunal, with chairman Jeff Gleeson saying in a statement explaining their decision that Cutis ‘did not need to propel Sinn forward with such force’, while also not doing enough to roll him to the side to minimise the chance of his head hitting the ground.

“A prudent player would have realised that in executing a tackle in this way carried with it a real likelihood of Sinn’s head making forceful contact with the ground with the potential for a concussion,” the statement reads.

“Curtis dropped his weight at the commencement of the tackle and to some extent, Sinn’s knees plugging into the ground caused the players to propel forward. That is not an unlikely or unforeseeable consequence of a tackle such as this in these circumstances.

Paul Curtis’ tackle on Josh Sinn left the Port Adelaide defender with a concussion. (Photo by James Elsby/AFL Photos via Getty Images)

“Players are today well aware that tackling a player from behind, where both the tackler and the ball carrier have some momentum, carries a risk of causing a concussion if care is not taken to avoid or minimise that risk.

“Curtis did not do nearly enough to address that risk. As a result, he engaged in careless, rough conduct.”

The Tribunal also dismissed the Roos’ claim for impact to be downgraded.

“As for impact, the video shows that the force with which Sinn’s head hit the ground was significant indeed. He was clearly hurt and visibly distressed. He took a considerable time to get to his feet and left the field looking somewhat unsteady,” their statement reads.

“He has been diagnosed with concussion, will not train for seven to 10 days and will miss one match.

“We have no hesitation in classifying the impact as severe. The charge as classified is upheld.”

Curtis is the first of three AFL players challenging suspensions at the Tribunal this week, with Carlton’s Adam Cerra and Adelaide’s Mitch Hinge also attempting to overturn one-match bans on Wednesday morning (AEST).