St Kilda star Jack Sinclair remains no certainty to play Round 1 against Geelong as he continues to deal with a calf issue.

The dual reigning best and fairest winner remains up to three weeks away from returning to full fitness, with Sinclair one of several Saints currently occupying the casualty ward at Moorabbin.

Defender Hunter Clark and midfielder Zak Jones will at least miss this week's practice game against Essendon due to concussion, while forward Dan Butler (ankle) joins Paddy Dow (knee) in being in doubt for the club's season opener in mid-March.

Jack Hayes (knee) and James Van Es (ankle) still require some time on the sidelines following off-season surgery and could still be six weeks away, while Ben Paton underwent a successful procedure on a ruptured pectoral tendon.

“Hunter is currently training non-contact, but we won't rush him back this week,” Saints football manager David Misson said in a club update.

“Zak will continue to work through concussion protocols, which we will continue to monitor closely.

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

“As for Jack Sinclair, it's about making sure his body is tip-top for the season proper so we'll manage his workload over the coming weeks.”

The Saints will host Essendon at RSEA Park on Friday afternoon before a second pre-season clash with North Melbourne next week.

Ross Lyon's men travel to Kardinia Park for a Round 1 clash against Geelong on Saturday, March 16.