The Zimbabwean international joined the club from Golden Arrows after signing a five-year contract with the DStv Premiership champions.
The 26-year-old arrives at the club following the departure of Tebogo Langerman and will battle with Lyle Lakay for the left back position.
Lunga has now followed in the footsteps of a number of Zimbabwean legends who have worn the Sundowns jersey, including legends like Esrom Nyandoro, Cuthbert Malajila and current team manager Peter Ndlovu.
“I am settling in well, the guys are treating me well, they have welcomed me here in a good way,” Lunga told his club’s official website.
“Some of the players like to make jokes and I think that’s how I’m jelling in because I am that person who likes to laugh.
“I don’t talk much but when the guys crack some jokes, I am going to laugh and talk with them.”
