ADELAIDE midfielder Brad Crouch faces an extended period on the sidelines with a groin injury.

Crouch is expected to miss up to the first two months of the season, and would then need to prove his fitness through the SANFL before returning to the senior side.

He is set to be out for the next six-to-eight weeks.

Crouch had his training loads managed during the pre-season because of his injury history.

An abdominal strain forced him out of the JLT Community Series, but the groin issue is more serious.

It's an untimely blow for the 24-year-old, who has had an unlucky run with injuries during his 61 career games.

Crouch averaged 28.1 possessions in 20 games last season – the most games he's been able to play in a single season in his five years on the Crows' list.

He missed the entire 2015 season with a serious foot injury.

"Brad Crouch has been returning from his abdominal strain and in the process of that, he’s flared up groin issues so he will be unavailable to play this week," Crows head of football Brett Burton told the club's website.

"Brad is obviously an important player to us and we take a no-risk policy with him given his previous history.

"He’s missed a quite a bit of training so we need to go through a re-conditioning phase with him now and that will be a six-to-eight week process.”

Defender Alex Keath has also been ruled out of Friday night's round one clash with Essendon at Etihad Stadium.

Keath rolled his ankle in the JLT Community Series game with Port Adelaide.

He is expected to miss only one week.

"If it was a Sunday game he (Keath) might have got there, but a couple of days short so we will get him right for round two," Burton said.

Keath's absence almost certainly locks in 2015 first-round draft pick Tom Doedee to make his senior debut.

Forward Riley Knight is another three to four weeks from returning from a foot injury, while skipper Taylor Walker is scheduled for a round two return from his own foot problem.

"Riley’s recovered really well from that ankle surgery," Burton said.

"He’s gone through a good rehabilitation phase and he’s back training with the main group which is a positive and we look forward to him being available in the next few weeks."

Draftee Andrew McPherson is also sidelined with groin soreness, with no timeline on his return.