City go into the game at the Etihad looking to continue their stunning start to the new season but the Spaniard insists his side can't take anything for granted against the lowly 'Hammers'.
Speaking ahead of the game, Guardiola reacted angrily to suggestions that the game would be an 'easy' one for his swashbuckling side, saying: "Don't say the word please!
"These kind of things happened in Barcelona. I was asked many times about that when we had good results.
"I spoke well about the opponents and people said 'Pep has false humility, he's a liar, he's saying something he doesn't believe'.
"I can't deny we're in better form than West Ham and have had better results, but tomorrow we start again."
West Ham boss David Moyes goes into the game still looking for his first win since replacing Slaven Bilic at the helm and fresh of the back of a 4-0 loss to Everton in midweek.
However, Guardiola insists that previous form counts for nothing once the whistle goes on Sunday and that City will be fielding their strongest possible side.
"I can't think it's already done or it'll be easy," he said "I can't think, 'It's West Ham we can make six or seven changes and the second team is going to play'. I think that's ridiculous.
"We have to respect them and the best respect to them is to be serious and play the strongest team possible."
Join us here on BeSoccer for live coverage of the game, whick kicks off at 17:00 CET.