ST KILDA co-captain Jarryn Geary will be sidelined for a period of time after injuring his shoulder during the Saints' loss to Sydney in round 12.

Geary will stay with the playing group in Sydney despite being unable to play.

It comes after the Saints flew mid-season draftee Cooper Sharman to Sydney to join the extended squad following the departure of crucial leaders Tim Membrey and Seb Ross due to family reasons.

The 20-year-old was selected by St Kilda with pick No.21 in last week's Mid-Season Rookie Draft, and was set to stay in South Australia, but Membrey and Ross' departure forced a change of plans.

Membrey and Ross flew home to Melbourne after the Saints dropped to 5-7 following the weekend's loss to Sydney at the SCG, with the rest of the extended squad remaining in Sydney.

Membrey's wife is due to give birth to their first child in coming days, while Ross' wife recently gave birth to twin boys.

The Saints are waiting for the green light to enter Queensland for the game against the Crows, with Membrey and Ross' return home to Victoria to add complexities to their ability to earn an exemption.

"Yeah, they headed home after the game on Saturday," Saints chief operating officer Simon Lethlean told SEN on Monday.

"So, they're not with us right now and I guess unlikely to join us for this game this week, wherever that might be. If it's in Sydney it's probably a bit easier, but if it's Cairns it's probably unlikely.

"They've both headed back for various reasons. Their intention is to be home this week and not be playing because they've got family matters to deal with and that's supported by us."

The Saints moved hotels across town on Monday morning and will spend the remainder of the week in Sydney.

Max King will be assessed after suffering a back spasm at training on Thursday, before playing and re-injuring his back during half-time.

The Saints are also working through options on co-captain Jarryn Geary's dislocated shoulder and whether surgery is required after he was unable to get it back in place for more than 20 minutes after the loss on Saturday.

They could be forced into four changes against the Crows with forward Mason Wood injuring his hamstring in the early stages against the Swans.