Coach Leon MacDonald said there was no doubting the importance of winning the game if the Blues were to contest the final in a fortnight.
"It's critically important. If you don't win it, you're out. We are playing it like it's a final, and we expect a tough game," he said.
"If we can get through the next two weeks, we give ourselves a chance of playing a final. This is the start of that. We've seen a good edge [at training], and the leaders have stood up well this week and driven a lot. I think the edge will be there.
"Suncorp is always hard for every team that plays there, other than the Crusaders a couple of weeks ago. I've played there, and it's a brutal place to play.
"We need to bring the right mentality, and that's about being physical," he said.
"We've got to front them physically. The big ball carriers they use at the line, the way that they hit. They're a big-hitting team. If we don't bring a level of intensity in that contact area, we're going to come second."
The way they had rebounded from a 63-28 hiding at the Crusaders' hands to claim a 40-34 win over the Chiefs was a reminder of the capabilities within the Reds.
"They brought a massive intensity. They were hurting after their game against the Crusaders, and they showed that in the way they took it to the Chiefs in the first half. We will be expecting them fast out of the blocks with a lot of physicality," he said.
MacDonald said arriving at this late stage of the season with a settled squad was great. They had achieved some continuity ahead of the last two games that will decide their season's fate.
Central to that is having captain and All Blacks lock Patrick Tuipulotu back to full form at the right time.
"We've graduated him back," MacDonald said.
"It was a significant injury, eight weeks with a sore neck, and we didn't want to rush him back too quickly. We were able to do that through the bench. He got good minutes the last two weeks, and now he's feeling a lot more comfortable."
Mindful of the need to cope with the Rebels' physicality, MacDonald has opted to start with Akira Ioane at No8 ahead of Hoskins Sotutu.
"There's not much in it between the two. Aki got the nod just because of his defensive physicality. He has been bringing a lot of intensity in his defence, which is a big part of our game.
"But expect to see Hoskins early as well. We're fortunate with two pretty special players to be able to use them the way we are," he said.