Chabangu, whose deal at NFD-bound Moroka Swallows expires on June 30, has been linked with a move to Wits since last season.
"He is training with Wits at the moment and nothing has been finalised or confirmed yet," Chabangu's agent Glyn Binkin tells KickOff.com.
The Bafana Bafana international has been a key performer for the Dube Birds since reviving his career in Soweto under Gordon Igesund in 2011.
Regarding Sheppard, Binkin says: "We are in the process of extending it for another year and he will be there.
"He has been a true professional on and off the field of play and conducted himself which has given him the longevity that he currently has.
"He is still a great inspiration to younger players."
Binkin believes the 36-year-old will make a fine coach when he eventually hangs up his boots.
"I'm no doubt that post-football he will be good in coaching because he understands the game.
"He understands the youngsters, he's got the passion for the game and the youngsters at Wits look up to him."