Manchester United manager is set to reignite his long-standing feud with neighbouring Manchester City boss Pep Guardiola by entering the race for Juventus defender Leonardo Bonucci.
According to ESPN, the Red Devils are keen to hijack Manchester City's negotiations with the Italian once they have completed the transfer of Bonucci's Juventus teammate Paul Pogba.
With representatives of City and Bonucci said to be in advanced negotiations, United will have to work quickly to ensure that a deal for the 29-year-old is not completed prior to Pogba's arrival at Old Trafford.
It is believed that during United's negotiations with the Italian champions over Pogba, the possibility of Bonucci making the same move was also discussed.
Mehdi Benatia's arrival in Turin had led many to believe that Bonucci's Juventus departure was imminent.
However the Old Lady will be unwilling to lose two of their star players, and could ask for a fee of £50m for the defender's services. A price tag that would see him become the world's most expensive defender should he complete the move.
Leonardo Bonucci: Only two outfielders have completed more long passes in the last four Serie A seasons than Bonucci (852)
Mourinho's former clubChelsea are also said to be interested in the defender along with the two Manchester clubs, with the Portuguese's replacement,former Juventus and Italian head coach Antonio Conte keen for a reunion with his former player.
A reunion at Stamford Bridge however now appears unlikely amid the strong interest of City and United.
Mourinho, currently on apre-seasontour with his players in China,appears desperate to bolster his defensive line at Old Trafford, with the Portuguese boss famed for the solidity of his sides.
Eric Bailly was the first recruit of Mourinho's era, a centre back bought in from Villarreal for a fee of £30m.
Mourinho's interest in another defensive addition has raised concerns over the future of current United players Daley Blind, Phil Jones and Marcus Rojo.