However, two weeks later the former Mamelodi Sundowns star came on as a half-time substitute in a 2-1 league cup win over Vizela, and managed to convince Martins to afford himself a maiden start in the proceeding cup clash, in which he bagged his first goal for the club.
The 24-year-old was then rewarded with his league debut against Braga in January, before going on to amass 19 starts in all competitions.
Zungu has credited Martins, whom he likens to his ex-coach Pitso Mosimane, for his progression from a B-team player to a first-team fan favourite.
"The coach is a lot like coach Pitso – he is also a father figure. He demands a lot from a player and if he can see you've got quality, he becomes even harder on you because he can see your potential," Zungu told KICK OFF.
"He wants you to reach the level he knows you can be at. I would play matches, and maybe the game would be quite easy for me, and I would take it lightly. Man, he would hammer me afterwards.
"Even in training he tells us we have to train [with the same intensity] as we would play in a proper match. He's a hard coach, he demands a lot from the players, and you have to run. If you want to play in his team, you have to run a lot.
"He doesn't have favourites, he plays people who work hard. Otherwise you are out." Zungu has also pointed out his coach's wishes for him to be a star player in the Uefa Champions League in the future, as he continues to encourage and support him.
"Our relationship has been awesome, he has helped me a lot," he added. "I can honestly say he wants me to grow and be a big player one day in the Champions League. He has told me he can see me there if I continue to work hard."