The Daily Mail says the former Barcelona boss has expressed reservations about working for Roman Abramovich and is said to have been surprised by Roberto Di Matteo's sacking only six months after leading the club to the Champions League and FA Cup.
Guardiola also knows that Abramovich has got through eight managers in nine-and-a-half years and is not convinced he will be allowed the time he needs to put his stamp on the club if he hits a bad run of results.
Furthermore, Guardiola is demanding total control of the club's footballing operation, something that has not always been permitted during the Abramovich era.
Guardiola's camp have also stressed to Chelsea that he wants to consider other offers. AC Milan officials have held talks with the Catalan's representatives, while Manchester City view him as a leading contender if they sack Roberto Mancini.