Lampard replaced Sarri following an impressive debut season in coaching at Derby.
Cesar Azpilicueta is hoping Frank Lampard will bring the glory days back to Chelsea.
Chelsea's record goalscorer replaced Maurizio Sarri at Stamford Bridge and Azpilicueta is convinced he will have a 'special' impact on the Blues.
The Spaniard also spoke of their below-par display last term, adding they are working hard under their new boss to give their supporters what they deserve.
"It is true that last season, for periods, we didn’t give the fans what they expected," Azpilicueta said as the Telegraph quoted. "Our performances were not good enough.
"We turned it around and won the Europa League but you can see that this season all of the fans are very happy we have the gaffer back at the Bridge.
"Now we have to give it back by working hard on the pitch, by winning games. We are very happy to have him [Frank Lampard] with us. I can’t add anything to his career at Chelsea as a player.
"But, over his first week in training, I’ve seen the way he wants to play, the way he wants us to feel the shirt, the way he wants us to train every day, it is something special."
The defender continued: "He was here for a very long and very successful period, and always set an example: how he wanted to break every record or improve himself in every session.
"We have to be grateful and feel the passion for the shirt. We are very excited and the only way we can carry it on is by winning together, getting the feeling back of being all together as a club.
"We have to take responsibility and know that there are a lot of things [going on] around us, but we have to work hard to get better."
Lampard's era as Chelsea head coach began with a 1-1 draw against Bohemians in the Blues' opening pre-season game in Ireland on Wednesday.