With Nat Fyfe suspended for two weeks and Michael Barlow missing for the same period with a broken finger, the Dockers need to find replacements in running positions.

The Dockers confirmed this afternoon they would appeal Fyfe's two-match ban at the tribunal, with the hearing to be heard in Perth tomorrow afternoon.

A top four finish and a double chance in the finals could come down to the outcome.

Hayden Ballantyne is due back from injury and could get a run up the ground as well against a Lions midfield that Lyon says are All-Australian standard.

“People from half-back, from half-forward, people who have played midfield in the past can go through there,” Lyon said.

“I think Ballers (Ballantyne) and Sonny (Walters) - I think Sonny will be a super midfielder one day for this club; I think he's clearly more than a small forward. His game sense and aerobic ability is of the highest order and he's so footy smart.

“So yeah, is it this week, maybe? But he will be an elite midfielder by the time he has finished.”

Walters played his first game of AFL last Sunday since having ankle surgery after the Dockers round 3 loss to Hawthorn.

He had 15 touches and kicked a goal in Fremantle’s 19-point win over Hawthorn; and had a light week on the track in the lead up to the Dockers game at the Gabba on Sunday.

The ability of the likes of Ballantyne and Walters to assist David Mundy, Lachie Neale and Stephen Hill in the midfield are crucial for Fremantle over the final two rounds of the home and away season.

To maintain fourth spot and the double chance in the finals, the Dockers may need to win both remaining games, including the round 23 clash with fifth-placed Port Adelaide.

But Lyon said his sights were firmly set on beating the Lions, who are coming off a 67-point win over Collingwood atthe MCG.

Brisbane has also had wins over Carlton, Gold Coast and North Melbourne at the Gabba this season, making them - in Lyon's eyes - a dangerous opponent.

“What they did in Melbourne was exceptional,” Lyon said of their win over Pies.

“They are quick... their midfield is probably an All-Australian combination at the minute, isn't it? (Dayne) Zorko, (Pearce) Hanley, (Tom) Rockliff and (Stefan) Martin and then you have little (Josh) Green.

“They are running it and gunning it. It's a big challenge (and) we're certainly taking it seriously.

"And on the back of us losing to St Kilda, we don't take anyone lightly.

“It's a sharp reminder for us all that there are no easy games in AFL footy.”

Meanwhile, Lyon said Fyfe had to be smarter with the way he acted on the football field, although he thinks the star midfielder is unlucky to be sidelined for two games.

Fyfe, one of the best players in the competition, was suspended for the second time this season after he struck Hawks midfielder Jordan Lewis behind the play on Sunday.

He won’t be available until the Dockers first finals game.

“I think that's (he needs to be smarter) obvious isn't it?,” Lyon said.

“He's a young player. I think what gets lost with Nathan is he's 22. But he's a real emerging leader of this football club; a really big influencer on and off the field, and he's a pleasure to coach.

“Lewis himself in his early days frequented the tribunal. It's just that competitive spirit. It's about harnessing it in the right way.

“In the heat of the moment, it doesn't take much to go wrong to find yourself in trouble. And clearly what compounds it is the system of loading and past penalties, where it's another 20 per cent loading or whatever from an offence that was debatable anyway.

“It might have been a week and we're all sitting here comfortable. I've got no real concerns there.

Nathan's an incredibly intelligent guy, focused firmly on team success and I'm sure he'll get the balance right.”