Speaking at a press conference ahead of Saturday's derby against Torino, manager Massimiliano Allegri revealed the right-back will need to undergo surgery for the ailment and will miss the club's remaining four matches in 2018 at least.
"Cancelo had a problem with his knee this morning, his medial meniscus," Allegri said Friday. "He'll be unavailable until after the break."
Juventus' first match of 2019 is scheduled for Jan. 12 when they take on Bologna in the Coppa Italia. They will then travel to Saudi Arabia to contest the Supercoppa Italiana against AC Milan on Jan. 16 before returning to Serie A action four days later against Chievo.
Cancelo was acquired from Valencia over the summer, with Juventus paying €40.4 million to sign the Portuguese international. The 24-year-old has blossomed into one of the premier full-backs in Serie A, starting in 15 games across all competitions this season for the Bianconeri and contributing four assists.
He spent last season on loan at Inter Milan.