West Coast co-captain Oscar Allen is set to spend a period of time on the sidelines after reporting swelling in his knee.
The club revealed Allen underwent scans in the wake of the Eagles' loss to Port Adelaide, where the injury was not initially discovered before, during or immediately after.
While West Coast will provide an update on the expected extent of Allen's knee concern, the club has confirmed their key forward will "miss some football" due to the ailment.
The injury comes as the Eagles deal with eight other players on their injury list one game into the season.
Injured midfielder Jai Culley (ACL) is as close as two weeks away, while Liam Ryan (hamstring) and Dom Sheed (foot) could mark their returns within the next month.
The Eagles are also hoping to have fringe defender Harry Edwards (finger) back next week.
"Liam and Dom are both progressing well. We expect to see them in pretty much full training this week," High Performance Manager Mat Inness told westcoasteagles.com.au.
"Now it's just a matter of building up their loads so hopefully we'll see them return to play in the next three-to-four weeks.
"Harry is starting ball work this week, so everything going to plan he'll probably miss this week but be back to play next week.
"Jai is going really well. He has been in full training the last couple of weeks, so he's probably another two weeks away from hopefully returning to play."
Alongside Allen, Rhett Bazzo (groin) and Elijah Hewett (foot) have uncertain return dates, while Archer Reid (knee) and Matt Flynn (knee) remain more than a month away.
West Coast return home this week, hosting GWS at Optus Stadium on Sunday at 6:50pm (AEDT).