Ganguly, who led KKR in the inaugral IPL last year, was stripped of the captaincy as Buchanan first spoke of multiple captains in the run up to the Johannesburg tourney, and then played a key role in installing New Zealander Brendon MacCullum.
Ganguly has already held a round of talks with KKR owner Shah Rukh Khan on the coach issue. The two are scheduled to meet again soon.
The sources said there was also a possibility of the team having an assistant coach from among former Indian players.
Speculation is also rife that Ganguly is set to get back the captaincy next year, though there is no official confirmation.