EXPECTATIONS for likely inclusion Rhys Mathieson ahead of Saturday night's showdown with Port Adelaide are simple, says Brisbane midfielder Jarryd Lyons.

"We don't expect anything over and above," Lyons said, following Friday morning's captain's run.

Mathieson is expected to replace injured Brownlow medalist Lachie Neale as one of two forced changes for the home team alongside concussed defender Darcy Gardiner.

Untried Irish defender James Madden was among the 25 Lions that trained and could be in line for a debut.

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Neale was an interested onlooker on Friday, watching from the boundary on crutches just four days after ankle surgery.

"He doesn't have to take over what Lachie's done," Lyons said of Mathieson.

"He'll come in and play his role and hopefully have a good game because he deserves it."

Coach Chris Fagan confirmed on Thursday the 24-year-old was all-but assured to come in after playing just one senior game since the middle of 2019.

Mathieson had an excellent pre-season and has been in terrific form at the lower level, kicking four goals to go with 18 disposals in a half of VFL action last Saturday.

"Honestly, for a bloke that has been one of the unluckiest footballers going around at the moment, his team-first mentality over the last six weeks has been amazing," Lyons said.

"He's been emergency every week, so he's always with our group.

"He's always happy, he's always up and about.

"He's the barometer for us, him and Charlie (Cameron) together.

"His energy has been awesome."

Lyons will play his 50th game for Brisbane after heading north from Gold Coast following the 2018 season.

It will be the first time since his arrival that he and Neale have not run out together.

"It's probably going to be different out there having one less leader in the midfield.

"He's been great to bounce ideas off.

"It just means guys like ‘Zorks’ and Zac Bailey and those sorts of guys are going to come through a bit more regularly and step up."