Manuel Pellegrini believes the tolls of an intense few weeks caught up with City at Anfield.
Following an action-packed ten days, which heralded a game in every competition, the Blues fell to a 3-0 defeat to Liverpool.
While the Chilean was of course disappointed with the result, he refused to accept the title race is over for his side but admitted an improvement is needed - and fast.
"It's an important defeat because we now have one game less and we couldn't win one point," he reflected.
"From the beginning, I saw the team were not recovered from the last week. It was intense with travel to Ukraine and the final.
"We did well in the Champions League and Capital One Cup but now we need to be focused in the Premier League.
"They were more fresh - they were winning high balls and they had high pace.
"In the first half, I thought it was very close. We didn't deserve to be 2-0 down because Liverpool didn't have many chances until they scored the first goal.
It is important to try and recover the energy we normally have. We have not played well in the last few games in the Premier League.
Pellegrini also confirmed the substitution of Raheem Sterling was not due to injury but merely a tactical switch.
He explained: "I wanted to play with another striker inside the box. We were not creating many chances in the first half and were losing 2-0.
"I tried to play Bony alongside Kun but we didn't improve."
As a result, City missed the chance to close the gap on league leaders Leicester, and lie ten points behind the Foxes.
With the Blues back in action with the visit of struggling Aston Villa on Saturday, Pellegrini is seeking an instant return to winning ways.
"I hope on Saturday we can return to our normal level of performance," he concluded.
"I said always the Premier League will be won by a team with 80 points or less - but we are not thinking about the title at the moment.
"It is an important gap - but we are not thinking about other teams."