The four-time African champions were in search of a fifth continental title but fell to Cameroon in the semi-finals and lost the third-place game to Burkina Faso.
Gyimah was the only player aside goalkeeper Fatau Dauda in the 23-man squad that did not earn a playing time for Ghana at the tournament.
“It was very disappointing,” Gyimah was quoted as saying by Kickoff.com.
“Ghanaians expected a lot from us and at the end of the day it didn’t go our way. So, we’ll have to go back, work hard and return,” he added.
At club side, Gyimah's Orlando Pirates are in search of a new coach following the departure of Muhsin Ertugral but he has called for calmness ahead of a new appointment.
“For now we don’t have to put pressure on ourselves at the club. We just have to keep on doing what we have to do. We expect good things. There is a new coach coming and we need to adapt to what he is bringing on board and everything,” he said.