They have won only one of their last nine games in Australia, while the Brumbies have won their last three games against the Highlanders.
However, the Highlanders are keen to take advantage of the opportunity to give injured players an extra week to recover because they knew their playoff fate before last weekend's loss to the Hurricanes.
First five-eighths Cameron Millar has recovered from a head blow against the Blues, while centre Tanielu Tele'a is back to strengthen the midfield.
Millar's role has advanced significantly during the year.
"What isn't seen is the work he is doing in the team. Behind closed doors, he's growing under the tutelage of the coaches, being around Rhys Patchell and learning from him. His delivery and confidence in our game have grown, and with that, his performances have grown, as well as his goal-kicking.
"It gives you an opportunity to put some scoreboard pressure on and in finals that becomes crucial."
In the pack, Mitch Dunshea is back to lock with Fabian Holland, while Sean Withy is returning to the openside flank.
The side is close to the best the Highlanders have fielded all season. They were set to take advantage of a solid end to the regular season. The leaders have stood up, and the best players have come through at the right time.
Dermody put the side's durability down to their pre-season changes in preparation under trainer Jimmy Holden, who joined the side for this campaign.
"We've changed the way we train and we've got more resilient players."
There has been a noticeable change in the side's preparation over the past few weeks.
But Dermody acknowledged Canberra is a tough place for teams from outside to win.
"The players are on edge, but it's a big week for the coaches too.
"We're happy with where we are at the moment. We got some things right against the Hurricanes last week, and we still had enough edge out of that game to push us into this week.
"We're looking forward to it."
They were used to being regarded as an underdog but haven't played on that in their preparation plans.
"It's more about the game that we've been playing and playing that the best we can."
Captain Billy Harmon said the Brumbies were playing good rugby. They have a great set piece and attacking backs, some of whom are the best in the competition.
"There's a lot of pressure, but we're ready. Their lineout is one of the best in the competition, and they've got a Wallabies first five-eighths who's controlling the game well. The outsides are electric.
"They love to get into that game of getting penalties, getting down into set pieces and squeezing teams that way. So, we've got to be clean."
Harmon said he would not be appearing for the Highlanders next season, but he wasn't going into the game as if it could be his last appearance. That would mean he wasn't in the right mindset.
Their review of their home game against the Brumbies showed several moments they let slip. They were not aware that, in the scheme of things, they were so vital, but in finals rugby, it was important to know when those moments were in front of you.
Harmon said sharing the captaincy with prop Ethan de Groot had worked well.
De Groot had been a leader in the team over the last few years, and nothing had changed.
"He's doing an awesome job. He stepped up as a leader this year. The boys get behind him. He's got a lot of emotion around playing for this team, playing in this jersey, so he gives a lot of that to the lads."