Sarri told a press conference that he was happy with De Ligt's form and fitness. The Dutchman is likely to come back into the team after Merih Demiral suffered an anterior cruciate ligament injury against Roma on Sunday:
"De Ligt is in great shape and the game against Roma confirmed that. I'm very sorry for Merih Demiral. It happened in a particular moment in which he was growing a lot, demonstrating that he's a Juventus player and having scored his first goal for the club."
Juventus announced on Tuesday that Demiral has undergone successful knee surgery in Austria and is likely to be sidelined for up to seven months.
Demiral has shone for Juventus this season and forced summer signing De Ligt on to the bench, but the 20-year-old now has the chance to cement his position in Sarri's starting XI until the end of the season.
Italian football writer Carlo Garganese said De Ligt will need to up his game:
Sarri also spoke about Ronaldo but refused to confirm if the Portugal international will start the match. The 34-year-old is in a rich vein of form and has 10 goals in his last eight Juve outings.
Ronaldo also scored twice against Udinese in the 3-1 win in December, as well as grabbing a hat-trick and an assist in his last home game:
The Juventus boss said he will speak to the forward ahead of the match and then make a decision on whether to include him in his starting XI.
"Our three forwards are all in good shape. Cristiano is fine and in great form and I want to speak to him tomorrow to find out whether or not to play him. [Marko] Pjaca is a great player who has been very unlucky. If there's a chance for him, I'll be more than happy."
Udinese arrive in Turin on a good run of form having won their last three games in row, but Sarri could make changes to his team as the Coppa Italia is not a top priority.