Juventus expect defender Alex Sandro to be sidelined for up to three weeks after he strained the flexor muscles in his right thigh.
The 25-year-old former Porto left-back had to be replaced by Patrice Evra in the 33rd minute of the Supercoppa Italiana defeat to AC Milan on Friday night.
The Old Lady were held to a 1-1 draw in the match held in Doha, before eventually losing 4-3 on penalties after extra-time.
After the game, the club revealed Sandro would undergo some tests before the full extent of his injury was revealed.
A statement from the club read: "Initial medical tests have shown that Alex Sandro strained the flexor muscles in his right thigh.
"The Brazilian full-back's condition will continue to be closely monitored over the coming days."
Juventus, who next play Bologna on 8 January, are also without Leonardo Bonucci and Dani Alves.