The Sky Blues' have fallen to their first home defeat since August at the hands of Forest Green Rovers.
Mark Robins' side created plenty of chances on the night but Keanu Marsh-Brown's first half effort was the difference between the sides at the Ricoh.
"I am really dissapointed. I am really frustrated. The usual things," said Robins.
"We created a lot of opportunities to score and we have not done it, yet again."
"It is a concern. We are going through a difficult week. We had a poor game on Saturday and tonight a poor result.
"We took too long to get our first shot on goal and then we become really anxious.
"We were looking to get efforts on goal as early as possible and we did not do that. Then there were some snapshots and then we had to force things and that brought poor decision making.
"You have to work hard, but relax. We were trying to score the perfect goal by the looks of it."
Again, it was a mistake at the back that lead to the visiting side at the Ricoh taking the lead, with Lee Burge this time struggling to judge Marsh-Brown's shot as it moved throught the air.
"The goal we conceded here was simular to the one we conceded againt Newport.
"That is the second goal we have conceded here this season where the opposition has not had to work for it.
"The ball moved a lot in the air, but it should not be hitting the back of the net. It made everything difficult for ourselves."
He added: "I cannot fault the workrate and the effort, but I can fault the decision making and I can fault some of the hurried and misplaced passes that were played without thought.
"We need to be calm. It is time to look at things and it is time to work, but yet again it comes down to taking the chances we create."