After hosting Shakhtar Donetsk on Tuesday, the Premier League leaders travel to Stamford Bridge next Saturday, with Antonio Conte's men first tackling a tough European assignment at Atletico Madrid in midweek.
Asked whether City's performances would strike fear into their opponents, Guardiola sharply replied: "Chelsea won 4-0 at Stoke City.
"And I think United have five clean sheets in a row [five out of six in the Premier League].
"It is such tough competition. All the big teams are strong."
Competition is similarly strong within Guardiola's squad, especially when it comes to the forward positions.
Raheem Sterling's brace against Crystal Palace took him to five for the season, the same amount plundered by Leroy Sane in all competitions.
Sane made only his second Premier League start of the campaign after Guardiola revealed poor form in pre-season left the Germany winger lagging behind his team-mates and City's other offensive talents are aware they cannot afford similar slips.
"It's not necessary for me to tell them, they know that," Guardiola said. "They feel their team-mates beside them and go 'wow, he is good'.
"That is the best way. You cannot play the same players every three days for 11 months. They have to play well. If you want to win, it has to be the best performance.
"Everybody has to push the other one."
City won their first six Premier League matches last season before a defeat at Tottenham began a wobble from which their title bid never recovered.
Guardiola feels his squad is in better shape this time around but still has ample room for improvement.
"When you analyse the numbers, no regrets, it's all good," he added.
"But the way we play, we can improve in many, many things and many concepts. That's what is next."