Pep Guardiola says repeating last season's treble is an "impossible" task for Manchester City ahead of their Premier League opener against Burnley, live on Sky Sports.
City won the league, FA Cup and Champions League last season to become the first English side since Manchester United in 1999 to win those three trophies together in the same season.
No Premier League club has ever won four titles in a row but Guardiola feels it is unwise to start talking about the title race in the opening weeks of the season.
"I don't think it's possible to do what we did last season. It's a once-in-a-lifetime," Guardiola said in his press conference.
"I said to the players, 'forget about it'. We have climbed the highest mountain with last season with what we have done. But the last two days we came down from the mountain with everyone else with the same intentions. There will be a lot of difficulties to climb to the highest possible part of the mountain.
"Our football, our behaviours and our mentality will dictate how our season will be. What we have done remains in our hearts and in our minds, how nice it was, but it's over. Every season starts from zero.
"But the history speaks for itself: when you achieve what we have done, it is impossible to repeat. We have to be aware of that and hopefully our fans and ourselves can understand how difficult it was and just try and get a good result against Burnley, against Newcastle and after that Sheffield United, game by game. No more than that."
Pep: Kompany's Burnley is a tough first game
First up for City is a trip to newly-promoted Burnley, who won the Championship last season under former City captain Vincent Kompany.
Guardiola hailed his former defender's work at Turf Moor and labelled the Friday Night Football task as a difficult proposition for his treble winners.
"Normally the first games are difficult in themselves, especially with the newly promoted sides because they have nothing to lose and they have the energy and the dream to have a good season," said Guardiola.
"Apart from that, Vinny knows us really well, he did an incredible job last season. He has changed completely the way Burnley were playing in the last few years with Sean Dyche and destroyed the Championship.
"Since day one, to win, win, win is so difficult in this competition and it's a fine and proper style from Vinny. It will be a tough, tough game, especially at the beginning of the season.
"The first game for the champions is so difficult. You need time to reset and we have to come back to where we were. That is a question of time."
Will Palmer and Walker leave Man City this summer?
Guardiola was also probed about the potential outgoings of Cole Palmer and Kyle Walker this summer.
Palmer is wanted by West Ham - who are trying to fend off City's interest in Lucas Paqueta - on a potential loan deal, while Walker is being courted by German champions Bayern Munich.
On Palmer's future, Guardiola said: "Today he is with us. What is going to happen I don't know.
"I understand he wants to be more active than the previous season, I understand that. But Riyad [Mahrez] is gone so there is one space there.
"I cannot say anything because all the players have a lot of desires. But the last decision belongs to the club. If you want to leave from here, it's ok. But you have to decide with the club."
And when asked about Walker's future, the City boss replied: "We are wishing that he stays, since a long time we have made him feel that. But no news."