Kick-off is at 15h30 at Loftus Versveld Stadium, with Downs seeking to ignite their title defence as they play catch-up in the league owing to their CAF exploits.
The African champions are in the Absa Premiership drop zone with four points from three games - 11 points adrift of third-placed Chiefs, who have played eight matches.
“This is a big game, and we all have been preparing well for the game,” Mohomi told the club's website.
“The spirit in the camp is high, and we all know that this will be a high intensity game. And then there is the matter of pride as well – and the winning mentality that is now ingrained in our side.
“We also know that the pressure is high, but that is what you expect when you play for a big team like Mamelodi Sundowns.
“We have undoubtedly one of the best coaches, and he knows how to prepare his team for any challenge.
“It’s not going to be easy, but we will do what we have to do.”