"I think part of this feeling that she is going to change [things] is the failure to understand how the AU operates. People might put a big burden on her shoulders expecting her to do this and that and when it doesn't happen, they will blame her when actually she has no capacity to do these things," Mbeki told the Sunday Independent.
The former president said AU policies did not originate from the AU Commission, which Dlamini-Zuma heads.
Mbeki said the AU depended on policy made by individual nations, with the commission only able to try and persuade them.
"You have to be able to intervene with the governments in a manner that encourages them," Mbeki said.
He said the AU had appointed a former Malian president Alpha Konare, for this reason.
"The reasoning was that once you have a former head of state sitting in this position of chair; he will have sufficient influence over his former peers," Mbeki said. "It didn't work."
Mbeki said Konare asked not to be re-appointed to the position at the end of his term.
"The people should not raise expectation with regard to the appointment of Nkosazana, which expectations will be disappointed," Mbeki said. – Sapa