The Reds have replaced star playmaker Quade Cooper with 24-year-old utility back Ben Lucas for their play-off with the Sharks in Brisbane on Saturday.
Lucas is the only change to the starting line-up which scored five tries to beat the Waratahs 32-16 last weekend while versatile Nick Frisby regains his place on the bench.
Lucas has featured in the flyhalf position for parts of 2012 and wore the No. 10 jersey against the Sharks in Durban earlier this season, where the Reds led 17-0 before he and Mike Harris succumbed to hamstring injuries.
He steps in for Cooper who is serving a one-week ban for a dangerous tackle on Waratahs inside centre Berrick Barnes last week.
Lucas, who has earned the bulk of his over 50 Super Rugby caps off the bench, regained the role once fit and led the Reds to victories over New Zealand's Chiefs and Blues,
Reds coach Ewen McKenzie said the group had full confidence in Lucas.
"Ben has been training at 10 all week and the guys around him are very comfortable with the direction he gives the team as he has gained plenty of experience in the playmaking role during the past two seasons," McKenzie said.
"Before last week against the Waratahs, we enjoyed arguably our best win of the season against the then competition leading Chiefs with Ben at flyhalf and we're confident he will get the job done tomorrow night.
"But it isn’t just about Ben, we have 21 other guys who will need to perform to ensure there is a strong platform for which we can launch our attack," said the Reds coach.
The Reds will have the added bonus of a strong home crowd, expected to be over 45 000, with the team having won 21 of their past 23 matches at their fortress, Suncorp Stadium.
"We've been given a huge opportunity to play our opening finals game at home where our record indicates that we lift another gear," McKenzie said.
"We've also had a strong week at training and you can sense the level of enthusiasm and excitement grow within the group. They're all looking forward to running out in front of a huge Suncorp Stadium crowd and a win would put us just one game away from back-to-back finals," he said.
Reds: 15 Luke Morahan, 14 Dom Shipperley, 13 Anthony Faingaa, 12 Mike Harris, 11 Digby Ioane, 10 Ben Lucas, 9 Will Genia (captain), 8 Scott Higginbotham, 7 Liam Gill, 6 Jake Schatz, 5 Adam Wallace-Harrison, 4 Rob Simmons, 3 James Slipper, 2 Saia Faingaa, 1 Greg Holmes.
Replacements: 16 James Hanson, 17 Ben Daley, 18 Radike Samo, 19 Jarrad Butler, 20 Beau Robinson, 21 Nick Frisby, 22 Ben Tapuai.
Date: Saturday, July 21
Venue: Suncorp Stadium, Brisbane
Kick-off: 19.40 (09.40 GMT)
Referee: Jonathan Kaplan (South Africa)
Assistant referees: Craig Joubert (South Africa), James Leckie (Australia)
TMO: Matt Goddard (Australia)