The 46-year-old Scotland-based tycoon has confirmed he held talks with Keegan in Manchester on Monday evening, and was hugely impressed with him.
Cleland's public statement confirms speculation over the last week or so that Keegan could make a sensational return to St James' Park following his resignation last month.
South African Businessman Backs Keegan!
Jonathan Cleland: "My meeting with Kevin went very well. I am hugely impressed with him and I got the sense there was good chemistry between us and there is a strong mutual interest in working together.
"He is our preferred option, but we cannot make any concrete decisions on the managerial position until negotiations on our planned takeover are further advanced.
"I think he understands and supports our concept of developing the club organically.
"I would say we are at least 80% confident of this working. We are cautiously optimistic, but we are not arrogant.
"I am a businessman who happens to be a supporter, and the club and the fans deserve better and we are hoping to achieve that.
"What we have to do is get the fans to come out and support the club in the coming games in their numbers and, in particular, to support the interim manager, who has such a challenge ahead of him.
"We would make it very clear that there is a clear hierarchy in place and everybody would fully understand who is calling the shots and who isn't.
"We would not necessarily throw the baby out with the bath water, but in any professional organisation, you have to carry out a detailed review of the human capital to establish exactly who has the capabilities you want and who doesn't.
"It would be inappropriate to discuss which individuals would stay and which wouldn't, and even at a later stage, it would be disrespectful to the brand to pass comment on people."