The Citizens head to Camp Nou on Wednesday for the latest showdown between the two sides, looking to improve on a record that has seen them come out second best in all four recent meetings.
Guardiola replaced Manuel Pellegrini at the Etihad Stadium in the summer and has already put his own spin on this City side, which Pique believes will make this week's Champions League tie a difficult one to call.
"Manchester City are a different team from last year and all the years they came here with Pellegrini," he told reporters. "Their style of play is different, they pressure a lot, very high, they try to have the ball and create chances.
"I think they play more or less the same style as us. Pep Guardiola was here a lot of years. Guardiola had an effect on us all. There was a before and an after. He changed the history of this club."
Barcelona have made a perfect start to their Group C campaign, winning two from two and scoring nine goals in the process.