The 30-year-old Italian signed a four-year deal with the La Liga champion after his success at Serie A.
He helped Juventus win three league titles in his four years at the club and the team topped four more points this season.
Deals for an experienced duo
Bosnian international action sees Barcelona’s Arthur head in the other direction, with Juventus paying the opening $ 80 million for the Brazilian.
Arthur joined Barcelona from Brazilian club Gremio in 2018, winning the league title and Super Cup in his debut season.
Like Plznick, the 23-year-old will not be leaving his new club until the end of the current season.
Juventus have agreed a year-long contract extension for both 35-year-old captain Giorgio Chiellini and 42-year-old goalkeeper Gianluigi Buffon.
The veteran keeper has played for Juventus more than 500 times since making his debut in 2001 and returned to the Italian outfit last year after signing with French champion PSG.