The coaching staff of England and South Africa are in a state of flux with South Africa Test captain confirming Ottis Gibson was the Proteas' preferred choice as new head coach.
Gibson remains contracted to the England and Wales Cricket Board is seen as key to their plans for the coming Ashes series.
But du Plessis made the announcement, which followed media speculation in both countries, at a press conference on the team's return to South Africa after Gibson had helped mastermind England's 3-1 Test home series win.
Incumbent Proteas coach Russell Domingo's contract will expire next month and although he had reapplied for the job, according to Du Plessis he is not the favourite to get it.
Cricket South Africa (CSA) convened a selection panel including former national team coaches Gary Kirsten and Eric Simons to identify an individual to take the team forward.
"It's been told to us that the decision has been made by the coaching panel," Du Plessis told reporters.
"They've chosen Ottis Gibson as their recommendation and now ... the board decides whether they want to use that recommendation or not."
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Du Plessis said he had already done extensive homework on his potential new coach.
"For me it was important, because I don't know Ottis, to try and find something out about him," he said.
"I spoke to a few of the West Indian players because he was their coach and then I spoke to the English guys about their thoughts on him.
"There were one or two differences in opinion, but the comments were positive."
Barbadian Gibson was coach of West Indies between 2010 and 2014 before rejoining England and taking up his previous role as bowling specialist.
England face a three-match series against the West Indies in their final Test engagement before this summer's Ashes, while the Proteas will hope their new coach, whoever it proves to be, will be embedded before the Australians visit in March next year.