WEST Coast veteran Drew Petrie has won a short-term reprieve from the axe, with ruckman Scott Lycett ruled out of Sunday's Western Derby against Fremantle because of a shoulder injury.

It was initially expected Petrie would be the unlucky player to make way this week for returning forward Josh Kennedy.

Petrie has played a vital role this season for the Eagles, with the 34-year-old holding down a key spot up forward as well as pinch-hitting in the ruck during Kennedy's six-week injury absence.

But last week's return of Lycett - and this week's inclusion of Kennedy - meant Petrie was on the chopping block for Sunday's derby.

Eagles coach Adam Simpson praised Petrie's selflessness, hinting the 323-game veteran would happily make way to allow the Lycett-Nathan Vardy ruck combination to flourish.

But Lycett's untimely setback means Petrie will be in the side for at least another week.

Lycett made a quiet return last week to AFL ranks, tallying just 12 disposals and 18 hitouts in a 32-point loss to Port Adelaide.

It was his first AFL match since pre-season shoulder surgery.

Lycett pulled up sore in his reconstructed left shoulder after the Port Adelaide loss, and West Coast's medical staff ruled him out on Friday.

It remains unclear whether Lycett will be able to return next week, but when he is ready, it seems Petrie will be the one to make way.

"We got Drew in as a back-up," Simpson said.

"He's willing to put his hand up when it's time to have a rest, or time to play at East Perth."

West Coast made four changes all up, with Kennedy, Will Schofield, Jackson Nelson and Chris Masten all returning.

Malcolm Karpany (quad), Eric Mackenzie (hamstring), and Lycett were ruled out by injury, while former Pie Sharrod Wellingham was dropped.

The Dockers welcome back veteran duo David Mundy (illness) and Lee Spurr (calf), with Tom Sheridan (hamstring) and Brady Grey (omitted) the two to make way.

Dockers coach Ross Lyon is confident defender Joel Hamling (hip) will recover in time to take on Kennedy.

The premiership defender will have to pass a Saturday fitness test.

And Lyon said Brad Hill was a definite starter despite the former Hawk nursing a sore calf this week.

Simpson said the return of Kennedy would be a big boost to his side's victory hopes.

"He's an experienced campaigner who's played well in big games," Simpson said.

"He's hard to play on. Even when he's having poor games, he's playing on the best defender.

"He's an asset to us."