— Genoa CFC (@GenoaCFC) September 19, 2020
Pjaca, 25, joins the Rossoblu from Juventus and it will be his fourth loan spell away from the club.
Since his €23m move to Juve from Dinamo Zagreb, the Croatia winger has made only 21 appearances for the club.
Pjaca been unlucky with injuries and will continue his career at Genoa following loan spells at Schalke, Fiorentina and Anderlecht.
Also arriving is 28-year-old Italy international Zappacosta from Chelsea.
The right-back was on loan at Roma last season but a serious ACL injury caused him to miss much of the season.
Zappacosta joined Chelsea from Torino in 2017 for a fee of €28m plus bonuses.