ADELAIDE'S midfield depth will be tested early with star on-baller Rory Sloane to miss the entire JLT Community Series with a fractured eye socket.

The All Australian vice-captain will undergo surgery after sustaining the injury during training on Friday.

In a statement, the Crows said they expect Sloane to be available for the club's round one clash with premiership favourites Greater Western Sydney at Adelaide Oval.

It's another blow for the Crows midfield with Brad Crouch also set to be sidelined for the pre-season competition with hamstring issues.

Meanwhile, defender Jake Lever will be sidelined for three weeks after sustaining a minor hamstring strain earlier this week at training.

Crows general manager of high performance Matt Hass said both players have had really strong pre-seasons up until now.

"Both Rory and Jake have done a mountain of work over this pre-season," Hass said.

"Unfortunately for Sloaney, he's fractured his eye socket during some contested work at training this morning.

"He will have surgery once the swelling reduces, which will likely rule him out of the pre-season competition.

"Jake has a minor hamstring strain which will keep him out for three weeks.

"We expect him to be fit in time for our last JLT Community Series game against Brisbane."