Italy legend, Alessandro Del Piero, told Chelsea to sign Juventus defender, Mathijs de Ligt this summer.
Tuchel is keen to bolster his defence this summer following the departure of Antonio Rudiger to Real Madrid a few days ago.
But Del Piero said it would be a good move if Tuchel signs De Ligt for Chelsea, adding that the former Ajax star is strong and fast.
“I think De Ligt has more pace and more potential than he has shown until now,” Del Piero told ESPN.
“He is playing a different way in Italy in terms of the system, in a line of four. How you address things [defensively] we do a little bit differently in Italy than in the Premier League.
“He also has the potential for physicality. He is strong, he is fast, and has no fear at all. That is why it could be a good move for Chelsea.”
He added, “On the other hand, Koulibaly is kind of perfect at this time, because of his age. He’s 31, he knows what to do. But if you want to buy a player, go for the youngest one, because you have more time to spend [improving him].”