Adelaide has suffered a double blow with the news that important pair Brad Crouch and Jake Lever won't be fit to face Collingwood at the MCG on Sunday.

Crouch, 23, will miss the Magpies clash after fracturing his cheekbone last week against Geelong while Lever, 21, will miss his second-straight game with a hamstring injury.

Crows coach Don Pyke expects Crouch and Lever to return for the massive round 20 Showdown with Port Adelaide at Adelaide Oval.

"Brad had the surgery on Tuesday and we spoke about the options with Brad and the surgeon's recommendation was it was too great a risk to put him out there this week," Pyke said.

"He was keen to play, but the smart management was for him to miss this week and we expect him to play the following week.

"Lever was a bit slower than we hoped to come back.

"He had a few targets from his running viewpoint he needed to hit and he wasn't able to do that this week.

"Not so much a conservative view, more the correct management of his injury and he should be fine for the following week."

Crouch showed courage to play out the final quarter of last weekend's win over the Cats after fracturing his cheekbone in the third term.

The inside midfielder is critical to the Crows winning the battle at stoppages – he's in the top 20 in the League for tackles (6.85), clearances (5.92) and contested possessions (12.62) per game to go with an average of 27.6 disposals.

While the Crows are optimistic Crouch will miss just one week, teammate Rory Sloane was sidelined for six games across two separate incidents in 2015.

Sloane missed three games when he fractured his cheekbone against Gold Coast in round six, then did the same injury in round 13 against the Brisbane Lions.

"That's always one of the possibilities and one of the risks playing this game," Pyke said.

"The chances of getting hit in the same spot are small, but as you've seen with Rory, it has happened.

"We're very hopeful it's just one week."

Key defender Kyle Hartigan trained on Thursday and is set to replace first-gamer Alex Keath after missing the past three games with a hamstring injury, while winger Wayne Milera (calf) is available.

The Crows also have to find a replacement for dynamic small forward Eddie Betts, who had his appendix removed on Sunday night and has been ruled out of the clash with the Magpies.

"He's a unique and special player for our footy club," Pyke said.

"Anytime you lose one of your best players and leaders of your footy club, it's a big out.

"With Eddie, we're hopeful he'll be back the following week."