MILAN, Italy -- ESPN FC's exclusive interview with retired Manchester United star Nemanja Vidic near his Milan home on Wednesday evening has already been running for one hour and 26 minutes on the record when the conversation turns to the current Man United defence.

A decade ago, the defender was playing for United at a rain-lashed San Siro in the 2007 Champions League semifinal. Now, a beautiful sunny spring afternoon turns into a lively evening, and Vidic has spoken about the 1991 Red Star Belgrade team, losing one of his best friends, war, his wife, cheese, Moscow, his pro coaching licence, and the many highs and occasional lows at an all-conquering Manchester United.

He has also mused about Rio Ferdinand, Sir Alex Ferguson, Paul Pogba, tactics and how Manchester has the perfect climate for football. Further, he speaks of the present and a player who has been tentatively compared to him. (The in-depth interview will appear in full on ESPN FC.)

"Eric Bailly started really well with a steady two or three months," explains Vidic, United's former captain who played 300 games from 2006 to '14 and was twice Premier League Player of the Season. "Then he was unlucky with injury and the African Cup of Nations. He's aggressive. He has potential, he's young, and he likes to defend. He has the qualities to go even further."

Bailly is the United defender Vidic picks out unprompted, perhaps because he shared those body-on-the-line similarities in style.

"But I still think that Phil Jones and/or Chris Smalling could build a partnership with Bailly," adds Vidic. "Smalling has the mentality to defend, the physical size to do it. He likes to defend."

The lack of a stable central defence since Sir Alex Ferguson stepped down in 2013 has been an issue for United, with injury preventing the type of partnership and subsequent understanding that Vidic enjoyed with Rio Ferdinand, and that Steve Bruce enjoyed with Gary Pallister in the 1990s.

"Communication is very important in defence, and it doesn't help when there has been a lot of changes in United's defence, like this season," adds Vidic. "It's important for central defenders to build partnerships. If you change too much, then it's difficult to understand each other.

"I was lucky to play for many years with Rio [Ferdinand]. Even though we were very different as players and personalities, I knew what he was going to do in any moment and he knew what I could do. That is absolutely vital for central defenders, but you also need a goalkeeper to communicate with you. David [de Gea] is brilliant and he's doing really well. He can also tell the defenders to speak more, to be more active in the game."

Nemanja Vidic, right, believes that a stable centre-back partnership is what's holding Man United back. Alex Livesey/Getty Images

Vidic also picks out his former teammate Antonio Valencia for praise.

"I loved playing with him and against him because he's an honest player. It's difficult to beat him one-on-one. He's strong, he's powerful, he has everything. I like to see him at right-back because he can still go forward and cross the ball, but he doesn't have that obligation to be creative too much up front. It's a good position for him."

But it doesn't take long for the conversation to swing back to United's issues in the middle.

"Rojo is a player who has done well at full-back for Argentina. Is he good enough to play central defence? Look, of course he's a good player; he plays for Man United most games. Can he play better? Of course. But if you're asking me which one central defender I most like to watch, then it's Bailly."

Vidic likes defenders who like the art of defending: the tackles, the duels, the one-on-ones where "I have to stop the man or the ball getting past me, at all costs," but he's uneasy about the current trend among top clubs of playing three at the back. United have also tried the formation recently.

"I played in a three at Inter and I didn't enjoy it," Vidic explains. "But a three can quickly become five, and if you have two wingers then it can be effective, but it's not how I see the perfect football team. I prefer 4-4-2, 4-3-3 or 4-2-3-1, but then each manager does the best with the players he has. I also know how football is changing and that Chelsea are likely to win the league playing three at the back.

"Three at the back may become the future, and Barcelona are the best example of the changes. Midfielders play as centre-backs, but if you play Barcelona then you're playing a team who will always attack."

Vidic played as a central defender throughout his career, but he has noticed that defenders shift more often now.

"Left-backs can play as central defenders," he says. "That wouldn't have happened before. Is the game changing or are there not enough defenders? I'm not sure.

"Do we want defenders anymore? I know what I like: defenders to defend. Defenders bring balance to a team and too many non-defenders can lose that."

It's evident that manager Jose Mourinho wants to improve United's defence, which has seen too many changes this season: There's no central defender in the top six of United's appearance-makers this season, and not one has started more than 14 of United's 27 Premier League games, with appearances split fairly equally between Marcos Rojo (14 league starts), Bailly (14), Jones (14) and Smalling (10). The latter two returned injured from international duty with England, welcomed by more sighs from United fans who are used to seeing them injured.

Mourinho wants another central defender and has been targeting Southampton's Jose Fonte, who signed for West Ham in January, and Atletico Madrid's Jose Gimenez since August. United's manager won't limit his searches to players who share his first name, but he wants the kind of stability he's seen from Valencia this season.

At left-back, Luke Shaw has struggled and barely played there, while an assorted cast has filled in. It's not ideal, and it's a long way from the stability United enjoyed when Evra, Vidic, Ferdinand and Gary Neville played week in and week out on their way to becoming champions of England. Or even Serbia's "famous four" defence, which conceded only one goal in 10 2006 World Cup qualification matches.

Vidic is 35 and has enjoyed life in Italy since retiring in January 2016 after a struggle with injury. Oh, for a clone of him in the current United side.