St Kilda has ruled captain Jack Steele out of Sunday's matchup with Port Adelaide due to an ongoing knee concern.
Steele was a late out ahead of last week's win over Richmond due to the injury and was listed as a test for Round 4, with the Saints deciding to initially name their skipper in their extended squad ahead of a trip to South Australia.
On Friday the club confirmed Steele won't be available for the clash, with young defender Arie Schoenmaker named in his place.
The Saints will need to reduce their 26-man side to 23 players come 5:00 pm (AEDT) on Friday, with Schoenmaker one of four potential ins for Ross Lyon's side.
Liam Stocker, Harry Boyd and Hugh Boxshall could also earn recalls, with Stocker returning after dealing with concussion.
Irishman Liam O'Connell is the only confirmed out for the Saints, having entered concussion protocols after his collision with Tiger Tom Lynch last Saturday.
Zak Jones, Lance Collard, Tobie Travaglia, Stocker, Angus Hastie, Boyd, Boxshall and Max Hall are listed on the extended bench, however named emergencies for the match can also be selected from the 18 players currently named on the field.
Like Steele, defender Jimmy Webster faced fitness tests this week after dealing with an ankle injury but has been named to play.
A win over the Power on Sunday would see the Saints' record go to 3-1 ahead of Gather Round.
St Kilda will remain in South Australia between their Round 4 and 5 matches, with the latter schedule seeing them face GWS on April 13.
