A bout of gastro has struck Melbourne senior coach Simon Goodwin on the eve of his club's September defence, with the Demons confident their leading man and players will be healthy come Friday night's qualifying final with Sydney.

The reigning premiers have been able to dodge niggling injuries and other health worries the past week as they set their sights on booking a place in the penultimate week of the season, with the Swans in their path as they start their post-season.

Goodwin's illness is understood not to have affected any of the player group.

Speaking to media on Thursday morning, Melbourne assistant Troy Chaplin revealed that while Goodwin has been placed away from the playing group, the premiership coach is expected to be available to move the magnets at the MCG this Friday night.

“He’ll be back on deck tomorrow, so I won’t have to worry about (coaching),” Chaplin said, via The Herald Sun.

“I’ll just continue on in my usual role and that’s just looking after the backs.

“He’ll be fine for tomorrow. (Adem) Yze will take the reins in that regard and look after it today and 'Goody' will be ready to go tomorrow night.”

The Demons are likely to make at least one change for their first final, with defender Christin Salem deemed fit to play after being a late out against Brisbane in Round 23 due to a groin issue, with Jake Bowey taking his place.

AFL Rd 4 - Melbourne v Geelong
MELBOURNE, AUSTRALIA - APRIL 11: Christian Salem of the Demons kicks during the round four AFL match between the Melbourne Demons and the Geelong Cats at Melbourne Cricket Ground on April 11, 2021 in Melbourne, Australia. (Photo by Quinn Rooney/Getty Images)

Bowey could be omitted for his fellow half-back, while any injury concerns surrounding Luke Jackson and Christian Petracca have been dashed.

Chaplin revealed that swingman Tom McDonald, who returned through the VFL last week from a foot injury, won't be risked for this week's matchup.

“What Tommy’s been able to do is get himself back... we just need to get some games into him,” Chaplin said.

“He’s given himself every opportunity, but missing that much footy with the injury he’s had, it’s just too much of a risk for him.”

The Demons will host the Swans at the MCG on Friday night, with the match to commence at 7:50pm (AEST).