Adelaide star Rory Sloane is in doubt for Friday night's clash with Sydney at the SCG, while midfielder David Mackay has been ruled out with concussion.

Small forward Lachlan Murphy will also be given another week to recover from a hamstring injury.

Half-forward Riley Knight is certain to come into the side for his first game of the season, while Curtly Hampton, Jordan Gallucci, Andy Otten and Myles Poholke all travelled with the extended squad from Adelaide Airport on Thursday morning.

Sloane has been battling a foot injury for the past couple weeks and looked below his best in last Friday night's 48-point loss to Collingwood at Adelaide Oval.

"He's still a bit sore," Crows coach Don Pyke told reporters at the airport.

"He's one that we've got to look at and decide what's best for Rory and best for the team to perform at the level we know he's capable of.

"Clearly in the last couple weeks, as much as he's been really willing, clearly his body is not in the space it needs to be to perform the way we know Rory Sloane plays."

While Sloane could miss the round five encounter with the Swans, Crows skipper Taylor Walker looks likely to take his place in the side.

Walker had a limited pre-season with a foot injury and has struggled to have an impact in the past couple of weeks.

"He's turned the corner a little bit," Pyke said.

"As is normal with guys who haven't done a lot of pre-season, they get a bit sore and maybe his load and his build-up was a bit more than his body was ready to cope with, and that's just meant we've had to manage him.

"He trained really well the other day and we're really confident with Tex and his availability this week."

Mackay was ruled out having been concussed twice in three weeks, while the Crows are confident Murphy will be available for next week's game with Gold Coast.

The Crows are also without All Australian small forward Eddie Betts, who will miss two weeks with a hamstring injury.

It makes the inclusion of Knight – who missed the first four rounds after ankle surgery – all the more important.

His ability to apply pressure in the forward line will be vital for the Crows after Pyke admitted they got the balance wrong against the Magpies.

"On reflection last week, we went in too tall," Pyke said.

"Knight is the sort of guy we have missed this season, he can not only get some good forward pressure on, but can give us some run in the midfield as well."