Appiah confirmed at a press conference in Accra on Wednesday that the AC Milan midfielder, who sat on the bench in the final group game, failed to join the rest of his colleagues in the pre-game preparations.
"I was notified by my technical team that he [Essien] did not warm-up though he was supposed to. It was reported to me and I have added it to my report," Appiah said.
"That was some minutes before kick-off against Portugal. Due to the urgency of the game, we had to carry on and after that I reported his conduct to the GFA in my report for the necessary action to be taken."
Ghana had a torrid campaign in Brazil, losing two games and drawing one to register their worst ever appearance since first making it to the tournament in 2006, with the decisive clash against Portugal ending in a 2-1 victory for the Seleccao.
Two players – Sulley Muntari and Kevin-Prince Boateng – were also sent home over misconduct allegations, while a dispute concerning the players' bonuses caused further consternation within the camp.
Ghana FA president Kwesi Nyantakyi noted that the governing body is "not going to condone any form of indiscipline" as they look to tackle the misconduct issues in Brazil head on.