NIC NAITANUI'S controversial suspension for a dangerous tackle is confusing for players, according to North Melbourne assistant coach Josh Drummond, who has called for greater consistency around whether it's the tackler's action or the outcome that dictates his penalty.

Naitanui was suspended for one match for a tackle on Karl Amon last Saturday that left the Port Adelaide midfielder with a mild concussion.

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The West Coast ruckman challenged his penalty at the AFL Tribunal on Wednesday night, arguing he had not breached his duty of care to Amon by tackling with excessive force.

However, the Tribunal upheld Naitanui's suspension, sparking a wave of criticism by past and present players.

North captain Jack Ziebell described the decision as "unfathomable".

Drummond told reporters on Thursday he had seen tackles by Naitanui earlier this season that had looked "very similar" to the Amon one but were cleared by the match review officer.

"(Naitanui) is just a big strong guy, like 'Maj' (Majak Daw). Maj has laid some really strong tackles the last couple of weeks and we're applauding him for it, but if coincidentally through the action the player's head touched the ground or hit the ground, Maj is in trouble," Drummond said.

"When the outcome dictates the penalty, then we're in trouble. If on one side we're applauding them, then the next if their head hits the ground we're suspending them, then as a player you're going, 'What do you want?'

"I think some consistency around whether it's the actual action that's the issue or the outcome would help everyone."

The AFL's legal counsel, Jeff Gleeson QC, told the Tribunal that Naitanui, at 110kg, had to remember he was roughly 30kg heavier than Amon when exercising his duty of care, arguing players regularly had to "compute" their height and weight compared to an opponent's ahead of contests.

Asked whether "big blokes" such as Naitanui and Daw had a duty of care to tackle differently to smaller and lighter players, Drummond said: "I don't subscribe to that."

Meanwhile, Drummond was optimistic North would regain talls Jarrad Waite (rested) and Daw (foot) for its clash against ladder-leader Richmond on Sunday at Etihad Stadium after both missed the round seven win over Sydney.

"(Daw) is tracking well, he's training today, so we're hopeful he and 'Waitey' will come up this week. It will just be how they train today," Drummond said.

"Maj has been a real positive for us this year, so we would certainly love to have him back."

Emerging defender Ed Vickers-Willis injured his right posterior cruciate ligament against the Swans when he crashed into a behind post during the final quarter.

Vickers-Willis missed the second half of last season with an injury to the same ligament and Drummond was unsure whether he would return before the end of 2018.

"He's obviously got his scans this week and some specialist appointments, so it doesn't look great for him. But in terms of exactly what rolls out of that we'll find out in the coming days," Drummond said.

"He's been a massive positive for us up until the unfortunate injury on the weekend. He's been super, it's a real shame for him.

"But the sort of character he is he had a bit of adversity over his first couple of years and last year and he bounced back, so this is just another little blip on the road for him.

"He's just got to do what we'll know he'll do and get back bigger and better."