The Netherlands centre-back is under contract at the Allianz Stadium until June 2024, but could soon be on the move after three years in Italy.
Chelsea has been linked with a move for the 22-year-old, who has been a regular in the heart of the Juventus defence since arriving from Ajax for €85.5million in July 2019.
The centre-half has racked up 117 appearances across all competitions, scoring eight goals, and winning the Serie A title during his first season.
In 87 Serie A games, he has committed just one error leading to a goal, yet Legrottaglie has not been wholly convinced by De Ligt.
With the Chelsea rumour now circling, Legrottaglie said: "If the boy was really convinced he wanted to leave, I don't know how much it would be better for Juventus to keep him at home against his will."
Legrottaglie, who also played for Italy, believes there are plenty of admirable elements about De Ligt's game.
"In terms of characteristics, I have always liked the player," Legrottaglie said. "I believe, however, that he has never really immersed himself into the environment.
"I have never seen real leadership from him; from the outside, he has been perceived as a bit separate from the group. Let's say he didn't do everything to make himself loved."
De Ligt remarked that Torino centre-back Gleison Bremer and Napoli's Kalidou Koulibaly might have the attributes to bolster the Juventus defence, after back-to-back fourth-placed finishes in Serie A.
He also pointed to the likely high cost of such players, and said: "It is not certain that with a great champion you necessarily do better, especially in defence. What counts is the work of the department, which often makes up for the quality of the individual."
De Ligt said talks about his Juventus future had been taking place, saying: "When the time comes, I will decide whether I will extend or whether I want to look further.
"I always look at what is best for myself in terms of the sporting project. Fourth place twice in a row is not good enough; we will have to make steps in that direction."