Xavi, 36, is currently playing for Al Sadd SC but won 14 major honours under Guardiola at Barcelona over four years.
He told BBC World Football: "If there is one person who can change the mentality of English players, of English football, it's Pep Guardiola.
"He is one of the best coaches. He could do a big revolution."
Listen to more from Xavi on BBC World Football
Guardiola won his first 10 games in charge of City before suffering a first defeat at Tottenham before the international break.
But Xavi - who left Barcelona in 2015 after winning his fourth Champions League title to play in Qatar - has seen enough from the club's early season form to suggest that Guardiola can make a big difference.
"If you see the games of Manchester City you can see his style," Xavi said.
"As a player he was a big reference for my career, and as a coach.
"We made history with him in Barcelona. Barcelona always have the best coaches but Guardiola made a revolution; not only at Barcelona but across the world.
"When you see him on the bench you can see his passion for football. I know him and I know he can do it."

President Raul Castro said "attempts to destroy the revolution" would fail.
Mr Trump has tightened restrictions on US travel to and business with the communist island.
But the US embassy in Havana, re-opened by former President Barack Obama, is still operating.
Mr Castro was speaking in front of Cuba's national assembly. It was his first public comment on the policy changes Mr Trump announced a month ago.
State-run Cuban media quoted Mr Castro as saying that Mr Trump was using "old and hostile rhetoric" and had returned to "confrontation that roundly failed over 55 years".
He said: "We reject the manipulation of the topic of human rights against Cuba, which can be proud of much in this area and does not need to receive lessons from the United States nor anyone."
Mr Trump anchored his policy rollback in human rights concerns raised by political opponents of Cuba's communist government, many of whom have fled to Miami where Mr Trump announced the changes on 16 June.
Mr Castro continued: "Cuba and the United States can cooperate and live side by side, respecting their differences. But no one should expect that for this, one should have to make concessions inherent to one's sovereignty and independence."
Mr Castro will step down as president in seven months, but will remain the head of the country's Communist Party.

The 66-year-old, of Ballybinaby, Hackballscross, County Louth, faces nine tax charges at the Republic of Ireland's Special Criminal Court.
Prosecutors claim he had significant dealings in cattle and land and received farming grants but failed to submit tax returns for nine years.
Mr Murphy denies the offences.
His defence lawyers claim that their client's brother, Patrick Murphy, managed his cattle herd and farming activities.
The prosecution at the three-judge, non-jury court was brought after an investigation by the Irish Criminal Assets Bureau (CAB).
One of the judges indicated that the verdict may be delivered next Thursday, 17 December, but added it is "by no means certain".
Mr Murphy was remanded on continuing bail until 17 December.
Former Barcelona midfielder Xavi believes Pep Guardiola "can change the mentality of English football" during his time at Manchester City.
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The president of Cuba has spoken publicly for the first time against US President Donald Trump's rollback of a thaw between the two countries a month ago.
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The trial of the prominent republican Thomas "Slab" Murphy for alleged tax evasion has heard the court may deliver judgement on the case next week.