The Bafana Bafana international rejoined the Brazilians at the start of the 2022/23 season but injuries – and stiff competition – have robbed him of regular game-time in the star-studded side.
Zungu says he will be patient.
"For me, it has been just about working hard [because] I'm playing for a team that is doing very well. It doesn't matter who starts, it's up to the coach who starts," said Zungu.
"For me, it's just to continue working hard, be patient and wait for my chance, and when that chance does come, I have to grab it with both hands."
Sundowns return to CAF Champions League action with their second group stage clash away to Coton Sport in Cameroon coming up tonight.
The 30-year-old left Sundowns three months before they were crowned African champions in 2016, when he moved to Portuguese side Vitoria Guimaraes.
One of the reasons why he returned to his former club, he says, is their ongoing ambition to compete for honours not only domestically but also on the continent.
"Well, I made a decision to come back and play for one of the biggest teams in Africa – a team with a growing ambition to succeed and compete against the best on the continent," he highlighted.
Kick-off is set for 18:00 (SA time). Catch the action live on SABC Sport on DTT Channel 4, Openview 124, SABC+ and sabcsport.com.