Adelaide are reeling from the loss of senior rebounding defender Graham Johncock to a broken thumb, ruling him out of the first month of the AFL season.

Shorn of numerous options in attack, the Crows had been counting on a settled defence and midfield to take into their round one date with Fremantle at Subiaco Oval on Sunday.

But Johncock complained of pain in his right thumb after Thursday's main session and scans on Friday morning revealed a fracture.

His loss will force Crows coach Neil Craig into a sizable re-shuffle, as he was already operating without the versatile backman Andy Otten, out for the year due to a knee reconstruction.

Before the session, Craig had mused that he had problems in attack - missing Chris Knights, Jason Porplyzia and Brett Burton - but could count on a more steady line-up elsewhere.

"There's no doubt with the injuries we've got, we're well served in defence, our midfield will be strong but (forward) is the area we need to be really diligent in the way we go about it," Craig said.

"(But) don't talk about injuries because it is forgotten, and not relevant.

"It needs to be relevant internally when you make decisions about where you're going, but from an external point of view that's the team you've got, and you get judged on the team you put on the ground."

Johncock's misfortune means a place in the travelling squad for Jarrhan Jacky, who was originally from Western Australia but has struggled to find a place in the Adelaide side.

The ability of Jacky or another youngster to slot in smoothly to play a role will be important as the Crows try to find some semblance of system despite their numerous injuries.

"Certainly at no stage of the pre-season cup were we able to get 90 per cent of our team on the ground," Craig said.

"Even in the last one we'd have had 12 players who would be considered to play in our first round not available.

"So was that a perfect preparation for us? No it wasn't."

Brought to you by AAP © 2024 AAP