After a four-year gestation period, the Pep Guardiola era at Manchester City begins in earnest on Saturday when his side tackle Sunderland in their opening Premier League fixture.

City began preparing the ground for Guardiola's arrival in 2012, when they appointed his former Barcelona allies Ferran Soriano and Txiki Begiristain as chief executive and director of football respectively.

Guardiola disappointed City by joining Bayern Munich in 2013, but the suspense finally came to an end last February when it was announced that he would succeed Manuel Pellegrini on a three-year contract.

Following a fourth-place finish in Pellegrini's last season, Guardiola is under pressure to mount a title challenge.

He has rejuvenated his squad with a glut of young signings, including John Stones and Leroy Sane, and is expected to get City playing the kind of slick, possession-based game as his Barcelona and Bayern teams.

It has been a close season of significant upheaval at City, who have also re-designed their club crest, and Kevin De Bruyne has warned that it will take time for Guardiola's methods to take effect.

"It's totally different, obviously. You see a lot of new things coming," said the Belgium midfielder, who only recently returned to training followed a post-Euro 2016 break.

"When you are later (arriving) there's a whole new thing, but I think I am getting most of it.

"I need some more playing time to know it perfectly well. But this is normal when you have lots of new things -- new coach and new players. We have time and it will come."

Guardiola has coached at the Etihad Stadium twice before.

His Bayern team produced a scintillating performance to beat City 3-1 in a Champions League group game in October 2013, which then club president Uli Hoeness said was "the best football I've seen in my life".

City claimed revenge a year later when Sergio Aguero scored twice in stoppage time to snatch a 3-2 win.

Moyes returns

Aguero will provide the focal point of Guardiola's new-look attack.

City's fans will have to wait a little longer for a glimpse of Sane, however, with the 37 million pounds ($48 million, 43.1 million euros) signing from Schalke nursing a minor hamstring injury.

Germany midfielder Ilkay Gundogan, signed from Borussia Dortmund, is sidelined with a knee problem, while Gabriel Jesus is on Olympic duty with Brazil and Marlos Moreno has been loaned to Deportivo La Coruna.

Stones, whose 47.5 million pounds transfer from Everton made him the world's second-most expensive defender, and Spain winger Nolito could be the only new signings to feature against Sunderland.

Stones's arrival is timely, with captain Vincent Kompany recovering from groin surgery and fellow centre-back Eliaquim Mangala out of favour.

Guardiola had to deploy a makeshift centre-back pairing in City's final friendly game, a 3-2 loss to Arsenal in Gothenburg, where midfielder Fernando played alongside left-back Aleksandar Kolarov.

In an extra complicating factor, City visit Steaua Bucharest on Tuesday for the first leg of their Champions League qualifying play-off.

Guardiola has described it as "the most important game for our season".

Returning to Manchester with a little less fanfare is Sunderland's David Moyes, who filled the vacancy at the Stadium of Light after Sam Allardyce was appointed England coach.

Moyes spent 10 unhappy months as manager of Manchester United and returns to the Premier League after a similarly underwhelming spell in Spain with Real Sociedad.

He has signed youngsters Paddy McNair and Donald Love from United, as well as Senegalese defender Papy Djilobodji from Chelsea.

"The first game is always difficult and we start against a big team in Manchester City," said Dutch forward Jeremain Lens, whose side avoided relegation by two points last season.

"As everybody knows, we finished last season with a good record and the new manager is trying to start this year as we ended the last. We have the players and we have the quality to do so."