Dougal Howard has been withdrawn from Sunday's match against Fremantle after entering AFL Health and Safety protocols.
Defender Darragh Joyce comes into the starting line-up for his first match of the season in Howard's absence.
The Saints have confirmed at least two changes to face the Dockers, with first-round draftee Nasiah Wanganeen-Milera and former Port Adelaide defender Jarrod Lienert coming in for Dean Kent (omitted) and Mitch Owens (omitted).
Sunday will mark Lienert's first game for the Saints after signing on as a rookie during the pre-season Supplemental Selection Period.
St Kilda's final team for Round 2 will be announced at 5:00pm AEDT.