Russell Domingo said Graeme Smith is wide of the mark in suspecting that all is not well in the South Africa camp and stressed that captain Hashim Amla has the full support of his players.
The Proteas were beaten by 241 runs against England in the first Test at Kingsmead this week after suffering a 3-0 hammering in India.
Questions have been asked about Amla's captaincy and there has also been talk of discontent in the South Africa dressing room, with former Proteas captain Smith expressing his opinion that there could be "a few rumblings" in the camp.
Smith also said he was not convinced by AB de Villiers' denial that he could end his Test career after the four-match series against Alastair Cook's men.
Domingo spoke of the need to close ranks after the defeat in Durban and the South Africa coach also dismissed talk of unrest.
He said: "Smithy is entitled to his opinion. From what I am aware, it seems a pretty happy camp. They are not happy with the performances but they are all supporting and backing each other and supporting the captain 100 per cent.
"The issues or the gripes that [Smith] is perceiving - I'm not too sure where they are coming from."
Domingo also backed South Africa's key batsmen to return to form ahead of the second Test at Newlands, which starts on Saturday.
He added: "When you have got players the calibre of Hashim Amla, JP Duminy and Faf du Plessis, with proven records, performances under pressure and big hundreds when it counts, you know they are one or two innings away from a big score and you've got to keep believing in that.
"Whether it's for five or 10 innings, I can't tell you that. You've just got to believe that they are going to make a score at some stage."