Jose Mourinho reportedly failed in his attempt to bring Leonardo Bonucci to Manchester United from AC Milan during the summer transfer window.
The frustrated Red Devils boss prioritised signing a centre-back during the off-season, only to miss out on a number of his targets.
United's long-running pursuit of Harry Maguire was well known, as was their deadline-day approach for Diego Godin, but The Sun reports that another high-profile defender was also on Mourinho's radar.
Bonucci instead returned to Juventus in a £31m transfer, though, a year after heading the opposite way, as United officials did not feel that he offered good value for money.
The report suggests that Mourinho wanted Bonucci for his wealth of experience in the backline, and the Italy international would likely have been open to a move, but he was not given the green light to table a concrete offer.
Jerome Boateng of Bayern Munich and Tottenham Hotspur's Toby Alderweireld were also touted as targets for United, as was Yerry Mina prior to his Everton switch.