"You know what happens in Wydad, you have seen games away. We need Denis in those games, and we want to make sure Denis is available,” Mosimane said.
"He could have played against Chippa United but we didn't want to risk him,” added ‘Jingles’.
After conceding once over the two-legged affair, Mosimane will pin his hopes on Onyango and other experienced campaigners in Rabat, who were rested for the domestic league win over Chippa on Tuesday.
"Also, the old legs Wayne Arendse, Anele Ngcongca and we've got to trust (Mosa) Lebusa and other players, so we rested them,” he revealed.
"We need fresh legs and we needed to give (Gaston) Sirino game-time. He has not played for long and you could see he was a little bit rusty and also give Vila (Sibusiso Vilakazi) time to play, and it's good Lebo Maboe is back," Mosimane concluded.