Ouro-Akoriko is making his way back from a sprained ankle, fellow defender and new signing Van Heerden had a calf strain, while Zimbabwean winger Karuru has yet to feature this season due to an ankle injury.
Ouro-Akoriko and Van Heerden face late fitness tests this week, with Usuthu’s team physio Karel du Toit indicating this weekend's contest may come to soon for Karuru.
“Sadate is returning from an ankle sprain. He is just struggling with a little bit of a bone contusion,” Du Toit explained on the club's website.
“But he is returning to full training. He has mild symptoms, but we will see how he progresses this week regarding availability.
“Marc van Heerden has recovered well from a grade one calf strain. He is also in full training.
“We will also evaluate him through the week of training and see if he can pass a late fitness test. But he looks good.”
He added: “Ovidy Karuru is still returning from quite a significant ankle injury. He is in full training.
“We just need to get him 100% comfortable at competition level.”
Defender Boiki Modisakeng and midfielder Sphesihle Maduna have also recovered from minor knocks.
Cavin Johnson's side, in fifth place on the log, will host the sixth-placed Brazilians at King Zwelithini Stadium (15h00 kick-off).