Despite reaching the competition's semi-finals, Samuel Boadu confessed that his squad struggled in the MTN FA Cup quarter-final match against Skyy FC.
The defending champions advanced with a goal victory against the Division One League side at the Accra Sports Stadium.
Hearts of Oak advanced to the next stage of the competition thanks to Patrick Razak's lone goal in the 66th minute.
"My team’s performance wasn’t good at all though we managed to get one goal. It is always difficult playing against Division One League teams," he said.
Accra Hearts of Oak are having an inconsistent run in the Ghana Premier League but their MTN FA Cup run is going well so far.
The Phobians will play Elmina Sharks in their next Premier League game.