Jose Mourinho must sell from his Manchester United squad before he can buy the central defensive leader he craves, club sources have told ESPN FC, pushing Juan Mata and at least nine other players further to the exit.

Having finally secured the world-record signing of Paul Pogba from Juventus to continue a productive summer in the market, the Portuguese remains intent on a commanding Nemanja Vidic-style centre-half to complete his team, but sources say he has been told the club will look to sell players first in order to balance business.

That is especially the case given that the profile of the defender that Mourinho wants would likely involve another big fee, especially with the lack of such players on the market. United have already informally spoken to Juventus about Leonardo Bonucci and Real Madrid about Raphael Varane.

The French defender has already turned down the Old Trafford club, though, while United themselves are wary of getting into more protracted negotiations with Juventus. And at the same time, sources say Bonucci is now much more reluctant to leave Turin than he was earlier in the summer, when Manchester City felt they were close to getting him.

Manchester United are eager to offload Juan Mata, left, and Adnan Januzaj, right, sources say. Laurence Griffiths/Getty Images

Meanwhile, Mourinho is willing to sell up to 10 players in order to trim his squad, with Juan Mata, Adnan Januzaj and Bastian Schweinsteiger the most high-profile.

As regards a signing like Mata, however, the United hierarchy want to ensure they at least recoup most of the £37.1 million they spent on him, with Everton showing some interest.

Mourinho has a net spend of around £145m this summer, having brought in Pogba, Eric Bailly, Zlatan Ibrahimovic and Henrikh Mkhitaryan. The only players so far sold for a fee have been Paddy McNair and Donald Love, both to Sunderland for a combined £5.5m.

That is likely to change over the coming days, as the Portuguese streamlines his squad.