The game has been moved to the ANZ Stadium in Sydney, scene of the Lions' series deciding victory, but Aussie skipper Horwill (calf) and Genia (knee) have been left out of the side by newly appointed Wallabies head coach Ewen McKenzie.
Both players are expected to be fit for the first week of the Super Rugby play-offs later in the month, but McKenzie has decided not to send them back into action at a venue where their dreams of holding onto the Tom Richards Trophy for Australia were shattered in a four try burst by the Lions a week earlier..
"I feel good, although obviously it'd be better not to have a calf injury. I was hoping to play this week because playing against NSW for Queensland is a big deal," said Horwill. "It's disappointing, but the plan is to be right next week to take on whoever we face in the finals."
The Reds lie fifth in the standings and are guaranteed to feature in the post-season, but can still finish as high as fourth and host a match in the opening week of the finals. Horwill led the Reds to the Super Rugby title in 2011.