Mark Robins was left “disappointed” after the Sky Blues were beaten by Reading at the Madejski Stadium on Tuesday night.
Goals from Lucas Joao, Andy Rinomhota and John Swift condemned 10-man City to defeat for the first time this year, with Kyle McFadzean shown a red card shortly before the hosts third goal.
The manager felt his side gave the game away against the Royals and wants his charges to be more clinical in front of goal.
Robins said: “We were playing against a really good team, but you can’t give them the goals that we gave them and they’ve not had to work for them at all and we’ve given them away.
“That’s something that we have to stop now, losing McFadzean didn’t help, but we kept giving them opportunities, before they scored again we had two chances to score and didn’t take them.
“We can’t let that be a factor in the second half of the season, we have to be more clinical, we’re going to have to be better, that’s where we’re at which is frustrating for everybody.
“We were good tonight if you take those mistakes out of it, they haven’t really created anything that has undone us, we’re disappointed, but we have to dust ourselves down and go again next week.”
Robins was pleased with the Sky Blues first-half performance, but was disappointed with how his side started the second period.
“We’ve got to keep working towards getting better results, this league is unforgiving and we could end up taking a defeat like this if we’re not tight with the ball and we weren’t in the second-half.
“The first-half was really good, we were keeping ourselves in the game and trying to take the opportunities that were coming our way because of the way we were playing and the way we finished the first-half.
“It was a really disappointing start to the second-half, to give the ball away with a square pass, the game is gone, we were bypassing the press in the first-half and created some really good opportunities for ourselves.
“Some of the play that we had was a positive, the set-piece deliveries and the chances we created from those deliveries was a positive, but there are too many negatives from tonight’s performance to be too happy about anything.”