Sundowns are in Ivory Coast and take on ASEC Mimosas at Stade Felix Houphouet-Boigny in Abidjan at 18h00 on a pitch that is not expected to do them any favours.
The Brazilians beat Mimosas 3-1 in the first leg played in Tshwane recently and a win tonight will take them to within one point of securing a place in the quarter-finals of the continental competition.
Mosimane says the CAF Champions League cannot be compared to domestic football because there are numerous things to take into consideration off the field.
"I want to win in Abidjan but Champions League is a narrow game. Look at the Lobi Stars game, we played well in the first half. We should have finished the game in the first half and the second half was a totally different game. It's Champions League, you have to understand,” said Mosimane.
"Lobi Stars played well against us especially in the second half but went to Abidjan and got hammered. Champions League is awkward. It's not the Absa Premiership where you could say 'this one can win against this one'.
"It's a different game. It's more than tactics. Lot of stuff involved. That's why it's Champions League. It's a tough competition, that’s why not everyone wins it. It's tough, it's tight.
"Orlando Pirates can confirm it. They scored a legitimate goal against Esperance and it was disallowed."
Midfielder Andile Jali could make a return to the starting line-up after recovering from injury.