FREMANTLE defender Ryan Nyhuis' dangerous tackle that knocked out Port superstar Robbie Gray is exactly "what you're not supposed to do", Power coach Ken Hinkley said.

Gray gathered a loose ball on the half-forward flank and attempted to evade Nyhuis, who wrapped up his opponent and slung him head first into the ground. 

Gray didn't stir until minutes after medical staff had tended to him. He was placed in a neck brace before being lifted onto a stretcher and taken into the change rooms. 

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The Power also face several weeks without influential ruckman Paddy Ryder, who came from the field during the second term with a hip flexor injury.

Hinkley said the incident needed to be looked at but, like his Brisbane counterpart Chris Fagan, dismissed suggestions of a red card policy.

"It’s a hard one – (the tackle is) exactly what you're not supposed to do," he said. 

"I don’t want to put anyone in trouble but that’s why the injuries come about. 

"Players don’t set out deliberately to cause injury like that but when you tackle and you take that responsibility away from the player, you put yourself in some trouble so clearly, there will be some trouble.

"It’s unfortunate that you lose your best player out of the contest through an incident like that … but, as I said before, I don’t think people deliberately try to hurt people."

Gray was in better shape post-match, with the club set to take a conservative approach with his recovery. 

"Robbie’s good as far as feeling OK inside, which is the most important thing," Hinkley said. 

"We’ll wait and see how Robbie is. Clearly we wouldn’t take any risks with a bloke like Robbie at any stage. We’ll make sure he’s OK.”

Ryder, meanwhile, appeared to land awkwardly on his left leg in a ruck contest before hobbling to the bench for treatment. 

"He’s got a hip flexor so he’s probably going to miss a little time," Hinkley said. 

"It was just in the contest – he just went to move in the contest and he said he felt it go. 

"We’ll wait and see what the scan says but there’s a significant chance he’s going to miss more than one (week)."

It is the second injury Ryder has suffered against Fremantle this year, after missing five games with an Achilles problem sustained in round one. 

Promising defender Todd Marshall failed to finish the Power’s SANFL fixture with what appears to be a serious ankle injury. 

Half-back Riley Bonner copped a knock to his left knee in a contest with Brad Hill but played out the match. 

The injuries follow that of important defender Tom Jonas, who suffered a "significant" knee injury last week.