Long forgotten now after romping to the Premier League with a record 100 points last season, City suffered some serious growing pains in Guardiola's debut campaign.
After Chelsea's defeat to the Cherries, Sarri admitted he was finding it hard to motivate his players.
'Then it was something that City lost three outside the top six teams, we drew twice.
Sarri acknowledged on Friday a return to Champions League football next season is Chelsea's target with a 12-point gap to City and Liverpool too big to bridge for the title.
Chelsea followed that result up with an impressive 5-0 home win over Huddersfield Town.
Chelsea manager Maurizio Sarri has remained optimistic about his team's chances of winning ahead of their Premier League clash against Manchester City on Sunday.
However, Sarri's admiration of Guardiola's team has not dimmed, and he said: "At the moment, in my opinion, Manchester City is the best team in Europe".
Meanwhile, Chelsea FC are in the middle of a somewhat patchy run of recent form, with the Blues having only won two of their last five Premier League games.
Unfortunately for Sarri he may not be allowed the time Guardiola was afforded given the lengths City went to secure his signature and also the trigger happy culture at Chelsea under Roman Abramovich.
"We need to defend very well and to be very fast when we recover the ball".
The defender has only featured in nine Premier League games this season, With Joe Gomez overtaking him in the pecking order.
"You have to be more competitive in the market or you need to work". We will try. We have to prepare well.
The reference to the transfer market may prove another significant difference. He also discussed the developing partnership the Argentine global striker has forged with Eden Hazard since his arrival.
"When some people were critical of the atmosphere against Leicester I was grateful that they filled the ground on a night when the weather wasn't the best and stayed with the team until the very end. Very, very good", Sarri said.