City only conceded with 20 minutes left to go in the game with Portsmouth, but it was the lack of determination as much as the eventual 2-0 loss that was the cause of frustration for the City boss.
"We had too many players not playing to the level that we know their capable of," Hughes told Sky Sports.
"Overall we didn't really deserve to get anything out of the game because we weren't forceful enough and we weren't determined enough.
"We had to make things happen and we found that very difficult today."
Away day bluesThe loss means that City remain with just one win on the road this season, having earned just seven points from a possible 39 on their travels.
Such dismal away form is threatening to drag City back into the relegation struggle, and Hughes insists that his side must learn to adapt their game if they are going to improve their points tally.
"Playing away from home we are finding it more difficult and I think there has to be an understanding that opposition teams won't allow us to play the football that we want to," the Welshman added.
"You have to find another way and at the moment we're struggling to find that other way."