"It's going to be a tight contest, very physical up front and tough at the breakdown because we know the personnel they've got."
Genia is still working on his partnership with new No.10 Mike Harris as Wallaby five-eighth Quade Cooper continues his comeback from knee surgery.
The Wallabies halfback also has to blend with the new centre pairing of Ben Tapuai and Jono Lance, who replaces the injured Anthony Faingaa at outside centre.
Horwill said Genia didn't get enough protection against NSW and was subsequently put under too much pressure.
"We need to be better. We probably didn't give him enough clean ball to our back line that we needed to," said Horwill.
"We need to be more clinical in that space, not only with out handling but with our breakdown work. We can't have guys counter rucking.
"The ball needs to be clean for Will to be able to do what he does best."
Horwill smiled when asked if he'd still be playing at the age of 34 like Force second-rower Nathan Sharpe, who's played 100 games for Australia and almost 150 Super Rugby games since 1999.
"He's done well at the age he is. It's a massive effort and for anyone to have that longevity in the game at the highest level is quite remarkable," said Horwill.
Reds officials are expecting more than 30,000 fans with Horwill urging them to make life tough for the Force.
"We're looking forward to getting back to Suncorp and hopefully it's a big crowd and they can make it as uncomfortable as possible for the Western Force," he said.