City set a host of records – including most points, most wins, most goals and biggest winning margin – as they powered to the Premier League title last term.
It was a memorable campaign but City boss Guardiola is well aware that rival teams and managers will be determined to improve and cut them down.
Speaking ahead of his side’s opening game at Arsenal, live on Sky Sports, Guardiola said: “We were the best, definitely, no doubts about that, but we don’t play alone. We can do our job but the others can do their job too.
“We can do our job the same as last season but maybe Liverpool or United, Arsenal, Chelsea or Tottenham can do much better and they win.
“We can be excellent but the others can be excellent too. We cannot deny the other contenders. There was a gap last season but this season I don’t know.”
Guardiola does recognise, however, that City do come into the new campaign from a good starting point following last season’s successes.
In addition to the title, City also won the Carabao Cup and they have already shown signs of maintaining the momentum by winning the Community Shield in comfortable fashion.
Guardiola said: “People say we now have to forget what we did last season. No way. I don’t want to forget that.
“I know exactly what we did to achieve that and we start from there. The principles are there. Now when I say something they know exactly what I want to do.
“Because of what we did last season now we are going to win? Nobody can assure me of that. We start again. That is why it is fascinating, it is a new challenge.
“But winning helps to win more. During the season we will have really bad moments – it is impossible to have the perfect season all the time – but when you win one title you can win another one. It helps for the future to know that.”
Guardiola has no doubt Arsenal, who are at the start of a new era under Unai Emery, can prove to be one of the challengers.
Emery replaced the long-serving Arsene Wenger at the Emirates Stadium over the summer and has immediately put his mark on the squad by overseeing five signings.
Emery arrives with a good reputation having won the Europa League three times with Sevilla and most recently worked at Paris Saint-Germain.
Guardiola said of his fellow Spaniard: “No advice [from me] – I think he has enough experience to know exactly [what to do].
“He is so intelligent. I have a lot of respect for this career – starting at the bottom and winning titles. He always makes his teams difficult.
“Now he is at Arsenal, one of the best teams in England, and he is a contender to win titles.”