But the self-belief is every bit a strong for Brisbane, who have fought through adversity to surge into Saturday's qualifying final at the SCG in red-hot form.
The Lions are strong favourites to pull off a smash-and-grab mission, with Sydney to again field an undermanned side in the absence of their suspended quintet.
Many critics have already ruled the second-ranked Swans out of flag contention, with stars Isaac Heeney, Chad Warner and Nick Blakey among the five players banned.
Even club chairman Andrew Pridham conceded the Swans' chances had been "torpedoed" in the fallout from events at East Melbourne's Pullman Hotel last month.
Sydney have only lost one SCG fixture this season - in round 19 to Adelaide - and are unaccustomed to being viewed as underdogs at home.
"If you are to be an underdog in any situation, it's not a bad thing," Rowbottom said.
"We still have a lot of belief in who's going out there and still have full belief that we can get it done.
"We've finished second (on the ladder), and we've earned the right for two home finals.Â
"We have full belief that we can win and then get a home prelim.
"If people want to write us off, they're more than welcome to do that."
Sydney are considered rank outsiders in betting markets, shifting the pressure on to Brisbane to book a home preliminary final.
If they do, it will be a significant step towards Chris Fagan's men booking a fourth successive grand final appearance.
Veteran defender Dayne Zorko is well aware the Lions have become the hunted again at the business end of a roller-coaster season.
"It's a great challenge for us," Zorko said.
"Whatever gets written externally about the team or whatever people are believing on the outside, for us on the inside, we know exactly what we need to do.
"The brotherhood that we have in and amongst our change room, the desire to continue to get better as well, that's a massive driving factor in why we've been able to achieve what we have."
Brisbane have overcome significant hurdles in the form of injuries to key players and a three-match losing streak mid-year, winning 10 of their last 11 matches leading into an eighth straight finals series.
"We're in a really good position, but honestly it accounts for nothing if we don't rock up tomorrow and get the job done," Zorko said on Friday.
Both sides made just one change to their teams that posted convincing victories in the last round of the home-and-away season.
Brisbane have been boosted by the return of star midfielder Hugh McCluggage, who has overcome a calf injury and replaces defender Ty Gallop.
Swans forward Joel Amartey (Achilles) remains sidelined, with fellow key forward Hayden McLean recalled in place of developing ruckman Will Green.
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