Mark Hughes thinks that a touch of battle fatigue finally caught up with the City side at Stamford Bridge on Sunday.
A solitary goal from Michael Essien was enough to give the hosts all three points, but City came up against a full-strength Chelsea side that had two extra days' rest after their own European exertions last week.
Mark said, "I think that our efforts on Thursday took a little bit of sharpness out of us that we needed today. Against a side like Chelsea you have to be dynamic and have a physical presence to drive the game.
"We did not have that in our play today, and our absentees would have helped in that respect. Maybe we were just a little lightweight in key areas, and as a consequence once we went behind we found it difficult to get behind Chelsea and cause them problems in the attacking third of the pitch.
"There's the disappointment of conceding a goal like we did, but we kept going. There was not a great deal of tempo to the game, it was slow and methodical and that suited Chelsea rather than us. We were always trying to get back into the game."
Essien's strike came off the combative midfielder's shin, the sort of attempt that had he hit it cleanly City keeper Shay Given may have stood a better chance of saving it. As it was, the luck was against City, as the Manager added:
"It was disappointing that we allowed Essien to get into that position anyway, but he took a swipe and got a bit of good fortune, it's looped over Shay's head and there was nothing he could do about it."
City were without the injured Vincent Kompany and Nigel de Jong, and Robinho came off towards the end of the game, but City are hopeful that a few days rest will do the trick ahead of Thursday's UEFA Cup tie in Denmark.
"We have a few bumps and bruises, Robbie has an ankle knock but hopefully it will settle down. Stephen Ireland was close to missing the game today, we are asking the same players time and time again to go back into battle for us and today was a little bit too much to ask. They gave us everything they had, but on the day we just did not have enough to open up a very good Chelsea side."