They previously worked together at Maritzburg United and during that time Zulu got his first Bafana Bafana call-up.
Zulu has played in both matches Middendorp has been in charge of since taking over from Giovanni Solinas and has shown some glimpses of brilliance in a more central role.
Zulu scored Amakhosi's opening goal against ASSM Elgeco Plus in the CAF Confederation Cup first round, first leg match at Moses Mabhida Stadium on Saturday, as the Soweto giants went on to win the tie 3-0.
Zulu played in midfield during the first half, but moved to left back when Godfrey Walusimi was taken off for midfielder Siphelele Ntshangase at the start of the second period.
"Zulu understands the football I want, he can track back and also attack when is needed. I think Walusimbi is still unfit or not fresh which made me use Philani," Middendorp said.
The German also spoke about rotating players in his first two games.
"I needed to change the squad because some players are injured, also others were not getting game time. I need to see the options we have so we can be in one page."
Amakhosi will open 2019 with a tough encounter against defending Absa Premiership champions Mamelodi Sundowns at FNB Stadium on January 5.
Middendorp revealed they have already started with preparations for that important clash.
"We open year with a tough fixture, we will have to work on our own before thinking about them, the connection in our style of play, it will be most important for us."