The Napoli and South Korea defender is a key target for the Red Devils this summer.
“I like him. I like him but for me, I haven't been overly impressed. Especially when I compare him to the likes of [Lisandro] Martinez and [Raphael] Varane," Silvestre told bettingexpert.com.
"I don't see him coming in and breaking that partnership.
“Especially when you have Lindelof who has done extremely well as a back-up. I think United are okay in that department."