West Coast will be without in-form forward Jake Waterman for their Round 9 clash with Collingwood at Marvel Stadium, while midfielder Elliot Yeo has been ruled out for at least two weeks.

Waterman - who's kicked 24 goals so far this season - has entered concussion protocols and will automatically ruled out for a minimum of 12 days, copping a head knock late in Saturday night's loss to Essendon.

The 25-year-old underwent a head injury assessment (HIA) post-game by the club's medical team and as a result, won't be available for selection.

As for Yeo, the 200 gamer has been in career-best form but unfortunately came from the ground in the final quarter nursing a groin strain.

The 2018 premiership player is understood to miss at least two weeks while scans will further confirm the timeline, according to Channel 9's Paddy Sweeney.

The Eagles premiership player will be sent for scans along with Noah Long, who injured his left knee while being tackled in the third term.

Adam Simpson's men will tackle the Pies, who have their own selection headaches to worry about.

Lachie Schultz (suspension), Beau McCreery (concussion) and Brody Mihocek (hamstring) are going to be fresh absentees for Sunday's clash at Marvel Stadium, with the latter expected to miss at least a fortnight.

It's also compounded by injuries to star midfielders Tom Mitchell and Jordan De Goey, with coach Craig McRae all but confirming they'll be sidelined this weekend.