The Catalan replaced Manuel Pellegrini as manager at the Etihad last summer, with numerous pundits tipping the former Barcelona boss, a two-time Champions League winner, for immediate success in England.
City started their season in stellar fashion, winning their first 10 games, but inconsistency and injury has since hindered the side’s pursuit of silverware.
The Manchester club now find themselves 11 points off league leaders Chelsea and out of Europe following defeat by Monaco in the last-16 of the Champions League.
The FA Cup represents the last chance for Guardiola and his men to get their hands on a trophy this season.
Speaking ahead of his side’s eagerly-anticipated clash with Chelsea on Wednesday night, Guardiola argued that his first season in charge will now be perceived as a failure in light of the high expectations initially cast over him.
"In my case I had to win the treble and change English football,” he said on Tuesday.
“Expectations were quite high, that's why I'm going to fall short definitely, I cannot have success this season.
"In Barcelona we won the three titles in a row, we played all the competitions, we played the Champions League every three days and we were able to play almost immediately. Sometimes you need more time.
"In spite of that [City’s inconsistent results] I think a lot of games we've played a lot of good football. I didn't expect that high level. But then also we were not solid. When they arrive 'wow they are going to create chances and score goals' and that does not help mentally or the confidence.”
Guardiola's City take on Chelsea at Stamford Bridge on Wednesday night and will be hoping to inflict further damage to their title campaign after Antonio Conte’s men were beaten by Crystal Palace at the weekend.
Chelsea slumped to their first defeat in 12 games as they struggled in vain to overturn the Eagles’ 2-1 lead.
Despite such setback, Guardiola believes City’s opponents won’t let Saturday’s defeat affect them heading into Wednesday’s showdown.
When asked if he thought Chelsea’s confidence would be damaged, the Catalan replied: “I don’t think so. They will be more focussed.
“When you win 10, 11 or 12 games in a row, the danger is to be relaxed. You are winning and have a points advantage. But when you lose a game, after that the warnings are there.”
Guardiola was also full of praise for the calibre of Chelsea’s forward game and their positional intelligence.
“Chelsea are good at set pieces and in the positional game, they are one of the best teams when it comes to using the third man and to set the ball in attack and runs in behind.
“David Luiz, [Gary] Cahill and [Cesar] Azpilicueta have the ability to play direct to [Eden] Hazard, Willian, Diego Costa and with Victor Moses and Marcos Alonso too, they are so dynamic so they use the counter attack, they are good at the positional game, they use all the aspects of the game.
“That is why they are one of the best teams in Europe by far and of course the counter attack with Hazard and Pedro and Willian, they are so, so fast, they run with the ball and they are so, so clever with the pass.”