The 29-year-old will return to his native country after spending four seasons on the Blues' books
Davide Zappacosta has departed Chelsea to join Atalanta on a permanent transfer, both clubs have announced.
The 29-year-old defender joined the Blues in 2017 from Torino and has spent the past two seasons on loan in Serie A with Roma and Genoa.
Zappacosta will now return to Atalanta, the club where he made his Serie A debut in the 2014-15 season.
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Zappacosta at Chelsea
The right-back signed for Chelsea in 2017, joining Antonio Conte's side after impressing with Torino.