VERSATILE St Kilda forward Blake Acres is in doubt to face Port Adelaide in China on Sunday after being struck down by illness.

Acres missed training on Friday at Jiangwan Stadium, where the Saints will face the Power in what looms as a huge clash, with both sides sitting 5-5.

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St Kilda football manager Simon Lethlean said Acres would be given until the last minute to prove his fitness.

"Blake wasn't feeling the best so stayed behind at the hotel to rest," Lethlean said.

"We'll continue to monitor him over the next day and he'll be given every chance to play."

Acres is averaging 16 disposals and has been used to pinch-hit in the ruck.

Hard-nosed skipper Jarryn Geary moved well in a relatively light session, wearing strapping over his right quad after three surgeries for compartment syndrome that saw his thigh sliced open.

The Saints did some match simulation work, but the 30-year-old appeared untroubled and is set to line up in the crunch contest.

Most of the St Kilda playing group landed on Thursday, having taken a direct flight from Melbourne.

The Power gave themselves an extra day to acclimatise the local conditions and have made the trip to China the past two years.

However, the Saints wanted to keep the trip similar to a normal interstate match, and by flying on Thursday it meant the players wouldn't have too much downtime, thus helping keep them mentally switched on.

A St Kilda traveling party of star wingman Jack Billings, tough backman Daniel McKenzie, CEO Matt Finnis and head of fitness Matt Hornsby made the trip to Shanghai late last year.

The day after landing, the players did a session when they ran about 7km and while they felt sluggish, pulled up well in the days following and were ready to go if a game had to be played.

St Kilda's fitness team has briefed the group about what to expect in terms of how they're feeling.

Also taking part in Friday's session were first-round draftees from 2017, Hunter Clark and Nick Coffield, along with key defender Darragh Joyce.

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