The Witbank-born star's two beautiful goals in a 2-1 win over Libya helped the nation qualify for the 2019 Africa Cup of Nations.
Tau, whose parent club is Brighton Hove Albion, had to be loaned to Proximus League side Royale Union Saint Gilloise in Belgium because South Africa were not in the top 50 in the FIFA Rankings.
"His touches seem to be a lot better, and quicker thinking, they seem to be helping him a lot. He can't go back to England because he doesn't have a... Bafana needs to come down in the rankings in that type of thing for him to get a work permit.
"You've got to come down to under 50 in the rankings and if Bafana are doing well in Egypt and are under 50 in the rankings... there's certain different criteria countries have to welcome foreigners."
The former Bafana Bafana captain also warned the country to guard against putting Tau under unnecessary pressure.
"Percy has done exceptionally well, let's just not pressurise him too much, let's just let him do his thing. The way he took his goals [against Libya], that was very, very good. I was very, very happy with his performance.”