The Blues turned to Sarri following the dismissal of Antonio Conte at the end of the 2017-18 Premier League season.
Chelsea FC won their opening five Premier League fixtures to hoist themselves to the top of the table.
However, Sarri’s men have drawn their last two Premier League games to lose ground on Liverpool FC and Manchester City.
Daniel Sturridge netted a late equaliser to rescue a 1-1 draw for Liverpool FC at Chelsea FC in the Premier League on Saturday evening.
Former Manchester United defender Ferdinand is impressed with Sarri’s immediate impact at the west London side.
“He has come in and brought real harmony in this squad as well as belief,” Ferdinand told BT Sport.
“They’ve all got an idea, he’s painted a picture [of what he wants] and they can see it. That’s a huge thing for a manager to be able to do.
“In this short space of time, that’s an achievement in itself.”
Chelsea FC finished in fifth place in the Premier League table last term to miss out on a Champions League spot.
The Blues managed to win the FA Cup title thanks to a 1-0 win over Manchester United after Eden Hazard’s winner.
The west London outfit have won the Premier League title in 2015 and 2017 under Jose Mourinho and Conte.
Chelsea FC will take on Vidi FC in their next Europa League fixture at Stamford Bridge on Thursday evening.
The Blues suffered a 1-0 loss to PAOK in their Europa League opener in Greece.
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