Tau completed his move to Brighton & Hove Albion in England and was subsequently loaned to Royale Union Saint-Gilloise in Belgium.
Mokoena played in Europe for over a decade, playing for teams like KRC Genk, Blackburn Rovers and Portsmouth.
“I told Percy Tau that he needs to win the fans when he gets there,” Mokoena told SAfm.
“I told him that he needs to work harder than the other players because he is a foreigner now. My challenge was to win fans but once you win the fans you are in there.”
Meanwhile, Mokoena is disappointed by South African players that come back to the local league too early after earning deals overseas.