Pirates head into the encounter eager to bounce back after their 14-match unbeaten run across all competitions was ended by Mamelodi Sundowns in a midweek Betway Premiership clash.
Despite the setback, the Buccaneers remain top of the league standings and are still on course for a remarkable quadruple, having already lifted the MTN8 and Carling Knockout this season.
Mthombeni acknowledged the scale of the task facing his side, particularly given Pirates' strong home record and passionate support, however, he believes mindset will be crucial on the day.
"I know it's difficult to play Pirates at Orlando because if you look at the results, they hardly lose there. The supporters also come in numbers, and that makes it even tougher," he said.
"Football doesn't have favourites. If we stick to our game plan and don't play with fear, anything can happen.
Casric arrive with confidence after a solid run of form. The Mpumalanga-based outfit are mounting a serious promotion challenge in the Motsepe Foundation Championship and extended their unbeaten streak to seven matches across all competitions in their most recent outing.
Known as the Believers, Casric booked their place in the last 16 by defeating Army Rockets in the first round of the Nedbank Cup. Now chasing a historic first-ever quarter-final appearance, they will be hoping belief, discipline and courage can help them spring a famous upset in Soweto.