The two teams will meet in the Carabao Cup final at Wembley Stadium on Sunday, and there's big pressure on Sarri, whose side sit sixth in the Premier League while City lead the standings on goal difference.
Chelsea's manager told reporters Guardiola required more time to implement his methods at City, similarly to how he may need at least a full season before he can thrive at Stamford Bridge:
"He (Guardiola) was lucky. I think that, if you choose Guardiola, you have to wait because the club knows very well that Guardiola needs time.
"It's not really very easy for an English team to play that kind of football, so it's normal. In the end, the most important things are the results. In my job, I need the result, nothing else. I don't know if I am under pressure from my club.
"It's important to win the final, otherwise you are second. I think it's very important for us because we have to find the confidence.”
City thrashed Chelsea 6-0 at home in the league just two weeks ahead of Sunday's Wembley showdown to illustrate just how far apart the teams are in quality.
Guardiola sympathised with his opposite number when he addressed the media in the buildup to the final, per Sky Sports:
Sarri's more controversial changes at Chelsea include moving N'Golo Kante away from his anchored role into a more advanced midfield position, assigning £50 million signing Jorginho as his anchor in the centre.
The Blues failed to record a loss in all competitions until November 24 but have already suffered five defeats in 2019. They lost 2-0 at home to Manchester United in the FA Cup fifth round on Monday, leaving them with one more chance at a trophy in the UEFA Europa League after Sunday's final.
The Blues will face Dynamo Kiev in the last 16 of the European competition.
Guardiola has been handed massive transfer resources since his arrival at the Etihad, however, and Sarri's record stands up to the Catalan mastermind's at this stage of his tenure, per OptaJoe:
Chelsea's chief recently defended himself against criticism of his maiden campaign in England, per ESPN FC:
Guardiola spent more than £140 million on players in his first transfer window at City following his arrival in the summer of 2016, while they sold Edin Dzeko and Stevan Jovetic for a little less than £25 million.
Sarri splashed £121 million on Jorginho (£50 million) and Kepa Arrizabalaga (£71 million) in his first summer, the latter being recruited out of necessity after Thibaut Courtois moved to Real Madrid.
Chelsea hold a cutthroat reputation when it comes to underperforming managers, though a League Cup win on Sunday may grant him more luck in the long run.