Ntanga, who was released by Arrows in January, is said to have been signed to add some experience following Zulu's failure to deliver goals for the Limpopo side since his arrival at the beginning of the 2018/2019 season.
Asked for clarity, TTM spokesperson Livhuwani Madzuhe said although Zulu's future with the club was still unclear at the moment, his performance was still being monitored.
"Zulu is not coping, " he tells KickOff.com.
"I think he will be one of those who will be released in January. But we are monitoring him. Ja you know these (NFD) boys they are running man. These NFD boys they mark, they don't give you a chance to relax. If they know you are a former PSL (player) they make sure.
"We've bought Ntanga. You know Ntanga he even scored in our last game when we beat TS Sporting 2-1.
"We need experience upfront in order to score those goals. We need to beef up because these youngsters upfront they are just running, they lack experience and we've got only [Edward] Manqele. David is not coming...from there we said no, let's just also call Ntanga and see if we can get a left-winger who can be a striker also."