PORT Adelaide ruckman Paddy Ryder is expected to miss a few weeks with a hip flexor injury, but All Australian forward Robbie Gray remains a chance to face Greater Western Sydney on Sunday.

Gray was knocked out by a Ryan Nyhuis sling tackle in Sunday's nine-point loss to Fremantle at Optus Stadium.

The 30-year-old returned to Adelaide with his Power teammates on Monday afternoon.

INJURY WRAP Star Port duo down

"At this stage, he pulled up really well," Power assistant coach Brendon Lade told reporters.

"After the game, he was eating and he was fine, he didn't have a headache at all.

"He'll be assessed on Thursday or Friday."

"The positive news is Robbie is fine, he's had no ill effects so far and hopefully he'll be fine for selection.

"He'll have to do all the (concussion) tests. If he's not feeling 100 per cent, he won't be playing."

Ryder didn't play the second half and he's set for another stint on the sidelines after an Achilles injury at the start of the season.

"He'll get scanned the next couple of days and we'll go from there, but it looks like he'll miss a few weeks," Lade said.

"He'll do his rehab, he's been very diligent with his Achilles and getting that right.

"If it's two weeks, if it's four weeks, who knows, we'll assess it by then."

Ryder's injury will likely mean key forward Charlie Dixon and swingman Justin Westhoff will share the ruck duties.

The Power adopted the makeshift tandem when Ryder was out earlier in the year and Lade said they would probably use that again.

"We thought it would disrupt us early in the year when we put Charlie on ball, or Westy on ball," Lade said.

"Charlie rucked the whole second half against Sydney when we were very good in that game, so we've learnt to adapt without one or the other in their specific areas.

"Taking Charlie or Westy out of the forward line - they're both doing OK up there - that will hurt, but it gives an opportunity for someone to do a role for us."

Exciting forward Todd Marshall could've taken that spot before picking up an ankle injury in Port's SANFL loss to Adelaide last Sunday.

"He was taken off on a stretcher, so you assume it'll probably be a couple of weeks," Lade said.

"We'll get it scanned and see what it's like and hopefully it's sooner rather than later."