Reigning St Kilda best and fairest Jack Sinclair's return timeframe remains up in the air as the Saints hope their dashing defender can overcome a calf injury.

Sinclair is set to miss this weekend's practice match against North Melbourne as he continues his recovery from the ailment, which has placed questions over his Round 1 prospects.

While the dual All-Australian has taken the needed steps in his rehabilitation, the club remains in the dark as to whether Sinclair will be available to face Geelong in mid-March.

If Sinclair is touch-and-go for their season opener, the Saints will then have to weigh up naming the 29-year-old or delay his return until Round 2 against Collingwood - an encounter that comes just five days after their first game of the new season.

Speaking to media on Friday, St Kilda defensive coach Corey Enright said the club will need to weigh up a number of factors to see Sinclair cleared to play the Cats, with the backman still needing to pass a number of tests also.

"He's going well, his program is just tracking along. We'll see where it lands in the next little period but there's been positive signs for Jack," Enright said.

Jack Sinclair during the round 22 AFL match between St Kilda and Brisbane on August 12, 2022 (Photo by Cameron Grimes / Zero Digital Media)

"We're still waiting to see (if he'll play Round 1). He has to tick a few boxes and has a few hurdles to get through to make himself available.

"(The short turnaround between the opening two games) does come into it. If you're looking at the longer term. That'll be up to the medicos and fitness staff.

"Hopefully he's there. If he's not Round 1 he's probably Round 2."

The Saints bolstered their defensive running stocks over the off-season, adding Angus Hastie through the National Draft before signing former Port Adelaide backman Riley Bonner to a rookie contract.

The latter was a standout in the Saints' opening game of the pre-season, flexing his line-breaking and running capacity in a convincing win over Essendon.

The Goodwood junior has quickly gained the respect of his teammate and Enright, who expressed his delight in the new recruit's promising start to life in the red, white and black.

"We picked up Riley Bonner as a mature player coming in. He played well last week," Enright said.

"He's come to a new club, he's trained really hard and earned the respect of the group.

"We drafted some young defenders as well this year. Whether they get a look in early stages this year, later stages this year or even next year.

MELBOURNE, AUSTRALIA - FEBRUARY 23: Riley Bonner of the Saints celebrates a goal with teammate Liam Stocker during the AFL 2024 Match Simulation between the St Kilda Saints and Essendon Bombers at RSEA Park on February 23, 2024 in Melbourne, Australia. (Photo by Dylan Burns/AFL Photos via Getty Images)

"We've got some really experienced campaigners in that group, but also some younger guys pushing up through, which is exciting."

The Saints remain hopeful midfielder Marcus Windhager will overcome a broken hand sustained in the win against the Bombers to be in the mix for Round 1, while key forward pairing Max King and Tim Membrey are primed to take on the Cats.

Small forward Dan Butler's (ankle) return is up in the air just weeks out from the start of the season, while Paddy Dow (knee), Jack Hayes (knee), James Van Es (ankle) and Ben Paton (pectoral) will all miss the opening round of the new season at the very least.

The Saints will make the trip down to Kardinia Park on Saturday, March 16 to open their season before hosting Collingwood at the MCG the following Thursday for what shapes as a difficult first fortnight for Ross Lyon's men.