City have accrued an incredible 198 points in winning the Premier League for the last two seasons, but their tally of 98 this season only pipped Liverpool by a solitary point.
Now Guardiola wants reinforcements this summer to refresh his squad, but also to try to remain a step ahead of their domestic rivals.
"Increasing competition is one of the reasons," said Guardiola whose City side face Watford at Wembley on Saturday hoping to add the FA Cup to the Premier League and League Cup trophies this season.
"The players have to feel that they play good or they don't play.
"I put it on myself, I have to win again. If not and I don't do it, I am in trouble and I cannot be here any longer.
"Football is what it is – win again and again and again and the players have to feel that. What we have done is incredible but from the first day of next season, we start from zero.
"We have to see what we have seen for the past two, even three seasons, and especially in terms of results for the past two seasons."
Guardiola's demands are so high because the threat from Jurgen Klopp's Liverpool is real.
Liverpool finished with 97 points this season and the City boss doesn't think the Anfield club are going to fall away.
"The history belongs to us for this title," he said. "But we know exactly one second later which team we are going to face next season.
"I am pretty sure Liverpool will be stronger and more hungry to do it, to break this 30 years without the league.
"That is why we have to stay there. If we don't, we are not going to win. They will be there the same.
"We will have to get more than 90-plus points to be champions next season. That is the level we have to maintain, to refresh our minds in the summer and to come back at the same level as these last two seasons."
If City are victorious on Saturday, they would become the first English team to win all three domestic titles in the same season.
But considering the players at his disposal, they must improve in the Champions League where they are yet to pass the last eight in Guardiola's three seasons.
"Of course it's our dream to do it, but I have to improve," he admits. "I have to see what I can do better to do it.
"In the same point, it's a more difficult competition, except (Zinedine) Zidane who is a master in the competition.
"For all the managers who stay ten to 15 years, they don't win this competition every season. Alex Ferguson only won it twice."
As Tottenham and Liverpool prepare to meet in an all-English Champions League final in Madrid on June 1, Guardiola can only look on enviously.
But the vagaries of knockout football, as opposed to the nine-month consistency needed to win a domestic league, have worked against him.
"The mistakes you can do, punish you a lot. We missed three penalties in quarter-finals or semi-finals, and went out for the difference of those goals.
"These kinds of little details, you get another chance in the domestic leagues."