Nigel Pearson says Saturday's heavy defeat at Millwall has left a lot for his players to work on during training this week.
The Tigers were on the back foot for long periods as they were beaten 4-0 at The New Den and Pearson says he and his coaching staff will be working hard to help eradicate the mistakes that cost City dear.
"Saturday gave an illustration of the work that we have to do," said Pearson.
"I've seen both sides of us now and there is a lot of work to be done. But it was the fashion in which we conceded the goals - if there is a hangover from last season, I'm not interested in that. We have to take responsibility for our own actions and that was a poor performance.
"Credit to Millwall, they're a good side who were well organised and that is typical of the games you get at this level. You have to be able to deal with that and we didn't on Saturday."
By the time the second half had kicked off and with City already 2-0 down, Pearson had made all three substitutions and he admits that was a sign of his disappointment.
"I think you've got to try things out. Things weren't very positive for us in the first half, although that's not to say there weren't passages of our play that were okay.
"But all four of their goals were preventable and it's disappointing when you concede in that fashion. We'll be working very hard to put that right."
