Pep Guardiola admits this season has been the toughest of his 16-year managerial career as Manchester City's Premier League title challenge collapsed and they exited the Champions League early.
The Spaniard has experienced little but success in glittering spells at Barcelona, Bayern Munich and City.
But after four successive Premier League triumphs, City's form nosedived from late October onwards.
They can still finish the campaign with a top-five spot and the FA Cup, while they have an additional shot at silverware at the Club World Cup.
But even if they end on a high note, it will not change Guardiola's verdict of the season as a whole.
"It's been the most difficult, that's for sure," said the 54-year-old, whose team exited the Champions League at the hands of Real Madrid in the knockout phase playoffs.
"It's been more demanding – much more. When you don't win it's more demanding emotionally and (in terms of) preparing and the moods and everything.
"It's been more difficult than the previous seasons when we played for the titles."
Injuries, particularly to midfielder Rodri, have been a huge factor in City's decline while a number of individuals have suffered a drop in form.
Guardiola does not absolve himself from blame.
"We had a lot of injuries, we didn't have the energy," he said. "We tried most of the time but we were not able to do it.
"I didn't find the way to let them feel comfortable and winning the games."
Guardiola, whose third-placed side travel to relegated Southampton on Saturday, admitted City's high standards had slipped.
"But, even with that, I would say, it could be worse. I was not good enough to find a way but we didn't give up," he said.
"We're still fighting to qualify for the Champions League – that is a big, big prize – and the FA Cup."