GEELONG'S main training session looms as crunch time for Max Holmes as the young gun attempts to prove his fitness from a hamstring injury for the AFL Grand Final.

Holmes was substituted out of the Cats' preliminary-final thumping of Brisbane last Friday night and appeared devastated as he lay face down on the sidelines.

But he was later cleared of a serious hamstring injury with both the Cats' medical staff and Holmes optimistic he can prove his fitness for Saturday's decider against Sydney.

Holmes trained away from the main group at Monday's open training session at GMHBA Stadium.

The young Cat carefully went through some exercises before moving on to running laps, to the delight of the big crowd.

The light intensity of Monday's session means Wednesday's main training shapes as Geelong's decision day on Holmes' availability.

Star teammate Patrick Dangerfield expected the Cats to give Holmes every chance to prove his fitness.

"A lot more (chance of getting up) than I did post-game, I think that's for everyone," Dangerfield told reporters.

"It'll obviously be left to the last minute.

"We've got wonderful medical staff and they'll make the best call for everyone involved but he's shocked a few of us."

Meanwhile Sydney is sweating on scans for versatile tall Sam Reid, who was substituted out of Saturday's thrilling preliminary-final win over Collingwood with an adductor injury.

Reid has proved valuable as a forward who can support Tom Hickey in the ruck.

Hayden McLean and Joel Amartey shape as potential replacements with Peter Ladhams still suspended.