The Italian defender completed a deadline day move to the Premier League champions from Serie A side Torino to improve their full-back options.
Zappacosta has established himself as one of the Italian top-flight’s best full-backs during a two-season stint at Torino before his switch to the Premier League.
The 25-year-old was called up to the Italian national team squad during Conte’s spell in charge of the Azzurri.
However, Zappacosta didn’t make his first appearances for his national team until November 2016 when Conte was already in charge of Chelsea.
And the new fifth signing of the summer transfer window for Chelsea was delighted to get the chance to work under the Italian coach again.
“I know him a little,” Zappacosta told Chelsea’s website.
“I trained with him for a few weeks when I played for the national team under him and from that small experience I gathered, he was a great manager who is always hungry for victory and wants to improve and progress, which is very good for the players because he can convey that philosophy to us.”
Zappacosta scored one goal and made five assists in 29 appearances in Serie A last season for Torino.
Chelsea have also signed Manchester City goalkeeper Willy Caballero, AS Roma defender Antonio Rudiger, Monaco midfielder Tiemoue Bakayoko, Real Madrid striker Alvaro Morata and Leicester City’s Danny Drinkwater.
The west London side have beaten title rivals Tottenham Hotspur and top-six contenders Everton in their last two Premier League games.
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