Guardiola expects Manchester United to rise in coming years under Ratcliffe
Ratcliffe, who has taken a 27.7 per cent stake in United and will have control over football operations, said he aimed to knock City and Liverpool "off their perch" within three years.
United have not won the Premier League since former manager Alex Ferguson retired in 2013 as City have become the dominant force in English football.
The blue side of Manchester have won seven Premier League titles in 12 seasons, five of which have come under Guardiola.
Ratcliffe has wasted little time in rejigging United's backroom staff, poaching Omar Berrada from City to be the club's new CEO and attempting to land Newcastle's sporting director Dan Ashworth.
"I think I am pretty sure with Sir Jim Ratcliffe and the other people, Manchester United are going to make a step forward," Guardiola said at his pre-match press conference on Friday, ahead of a trip to Bournemouth.
"I had the feeling they know exactly what they have to do, appointing people they need. With his experience in the business world, it can make the project better, but that is normal.
"All the teams want (to be at the top) and we want to be there. As long as I am here we will try to be there again."
Kevin De Bruyne could return for City on Saturday as Guardiola confirmed the Belgian is "not injured."
The midfielder spent the entirety of Tuesday's 1-0 win over Brentford on the bench due to what Guardiola described as "niggles" in his hamstring.
The 32-year-old missed five months of the season after tearing his hamstring on the opening night of the league campaign.
De Bruyne had been in scintillating form since his comeback in January, scoring two goals and providing seven assists in eight appearances.
City remain in the hunt to defend the treble of the Premier League, Champions League and FA Cup they won last season.
And Guardiola believes he was right to rest De Bruyne with so much on the line in the coming months.
"He's good, not injured," said the City boss. "I don't know if he is 100 per cent but we took a good decision to not take a risk, apart from the result.
"If the result was not good, people would ask why he didn't play. He didn't feel comfortable.
"The day after the game he didn't train and yesterday everyone was off, but he trained by himself. Today we will assess. I am sure he will travel."
With Liverpool not in Premier League action this weekend, victory for City on England's south coast would close the gap at the top of the table to just one point.