ADELAIDE will be without Matt Crouch for the next three weeks, with the reigning best and fairest sidelined with a left hamstring injury.

Crouch left the ground in the second quarter of the Crows' 36-point win against Richmond at Adelaide Oval last Thursday night.

The 22-year-old midfielder made the All-Australian team for the first time last year, and won the Malcolm Blight Medal as the Crows' club champion.

"It's a pretty straightforward hammy, low-grade," Crows GM high performance Matt Hass told afc.com.au

"We expect him to be out for about the 21-day period."

Star midfielder Rory Sloane (foot strain), forward Tom Lynch (illness) and midfielder David Mackay (concussion) need to prove their fitness for Saturday night's clash with St Kilda at Etihad Stadium.

However, key defender Daniel Talia is available after hyper-extending his knee against the Tigers, while midfielder Curtly Hampton has recovered from an adductor injury.

Forward Riley Knight (foot) has also been cleared to return.

Experienced recruit Sam Gibson will have to wait at least another two weeks before making his Crows debut, with his hamstring strain recovering slower than expected.

Gibson, 31, was a late scratching from the Crows' round one loss to Essendon, injuring his hamstring in the club's final training session the day before the game.