Rennie thought Messam had started the season quietly but had picked up in the victories over the Kings, Highlanders and Blues that followed the loss to the Stormers.
It is clear Rennie and the Chiefs see the Reds' counter-attacking threat as particularly dangerous. While the Reds are missing injured wing Digby Ioane, replacement Rod Davies will be one of the quickest on the field.
Ben Tapuai, thriving after a move to second-five, is, like Genia, in impressive form.
"They've got threats all over the park," said Rennie. "Obviously [flanker Liam] Gill's very good over the ball, as are a number of their guys. We need to get them off the pill quickly.
"We're well aware of how they went through us last year [a 42-27 loss for the Chiefs at Suncorp]. We've put a lot of emphasis on our defence but also when we have the ball because even though we've scored the most points in the competition we're not where we want to be yet. We know we can be better."
The Chiefs beat the Reds, who also had a bye last weekend, on the Sunshine Coast in a pre-season match but have lost the past three competition games against them.
Ben Tameifuna gets a rare start at tighthead prop. The other change to the team who beat the Blues at Mt Maunganui sees Tim Nanai-Williams on the wing after recovering from a groin injury.
Chiefs: Gareth Anscombe, Tim Nanai-Williams, Richard Kahui, Bundee Aki, Asaeli Tikoirotuma, Aaron Cruden, Augustine Pulu, Liam Messam (c), Sam Cane, Tanerau Latimer, Brodie Retallick, Michael Fitzgerald, Ben Tameifuna, Hika Elliot, Toby Smith. Reserves: Rhys Marshall, Michael Kainga, Nick Crosswell, Fritz Lee, Brendon Leonard, Andrew Horrell, Patrick Osborne.
Reds: Jono Lance, Dom Shipperley, Anthony Faingaa, Ben Tapuai, Rod Davies, Quade Cooper, Will Genia, Jake Schatz, Liam Gill, Eddie Quirk, James Horwill (c), Rob Simmons, James Slipper, James Hanson, Greg Holmes. Reserves: Albert Anae, Ben Daley, Ed O'Donoghue, Jarrad Butler, Ben Lucas, Chris Feauai-Sautia, Aidan Toua.