The 19-year-old defensive midfielder was promoted from the Multichoice Diski Challenge side.
Pirates head coach Milutin Sredejovic believes Mbulu is ready for the challenge of playing in the first team.
“Mbulu has left a really good impression,” Sredejovic told the club’s website.
“I have been monitoring him over the past few months at SAB level. He has also been training with us for a couple of weeks, where has shown that he is ready to take the next step.”
Mbulu joins Lyle Foster as the second player to be promoted to the Pirates first team this season.
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