They might be 80 minutes from away their first grand final in 25 years, but Josh Hodgson says Canberra will be taking nothing for granted when they face South Sydney on Friday night.

Having earned the week off after their last-gasp win over Melbourne in the opening week of the playoffs, the Raiders enter their first preliminary final as the warm favourites.

But Hodgson was not buying into any such talk, saying this team could not expect to just turn up and be handed victory against a side that finished above them on the ladder.

"It doesn't sit with me, I don't think we are favourites to be honest," Hodgson said.

"It's our first semi in three or four years, I'd say they have more experience in semi-finals. Just because we beat Melbourne in Melbourne, doesn't make us favourites."

Hodgson knows he and the rest of the middle forwards will have a crucial job to do in the first 20 minutes at a packed GIO Stadium as they look to blunt the dangerous Rabbitohs pack.

Raiders v Rabbitohs - Preliminary Finals

"They can get that roll on and you've got to be physical in the middle every single game but especially against these guys," he said.

"Tom, George, Sam [Burgess], Liam Knight all of the other front-rowers they have, they can get some quick play the balls and some second phase and then off the back of that Damien Cook's electric."

Souths were dealt a major blow on the eve of the games with James Roberts ruled out due to a thumb injury, resulting in Campbell Graham being shifted into the centres and Corey Allan included on the wing.

Jarrod Croker was not buying into the talk the Rabbitohs were outsiders even in the wake of Roberts' injury.

"They're a good side and they're coached by one of the best," Croker said.

"It's a prelim final, it's two sides and a 50-50 battle, they're going to be a lot better than they have been the last couple of weeks, we're expecting them to play their best game of the year.

"Just because it's our home game doesn't mean it's just going to happen for us, we've got to play our best game of the season as well."

However, the co-captain and leader of the Raiders did agree Friday night was the biggest game of his career, saying he was trying to keep a lid on expectations despite the city of Canberra being swept up in Raiders fever.

"We had the prelim a couple of years ago which was obviously the same scenario but getting through week one and having the week off and the build-up into a home prelim, it probably is [the biggest game of my career]," Croker said.

"I've seen it a little bit in the past but there's a fair bit flowing through social media, all of the [green] cupcakes, donuts and coffee.

"It's good so you've got to enjoy it because it doesn't happen very often, so you've got to enjoy the little moments, but I'll make sure the boys are switched on a right to go.

"It's good for the community, my mates have been ringing me up, I think they're more excited than me."