Manchester United manager Jose Mourinho is intent on signing a commanding centre-back to bolster his defensive ranks before the transfer window shuts at the end of the month.
Sources told ESPN that Mourinho is keen to add to his defence ahead of the new Premier League season despite signing Eric Bailly for £30m ($40m) from Villarreal earlier this summer.
The Portuguese reportedly wants to sign an experienced defensive leader in the mould of former United captain Nemanja Vidic to marshal the back four.
United bosses have reportedly discussed the possibility of signing Jose Fonte from Southampton, but Mourinho wants to assess all his options before making an official approach for the Euro 2016 winner.
The Red Devils remain interested in signing Leonardo Bonucci from Juventus but are wary of more lengthy discussions with the Turin club as the Paul Pogba transfer saga rumbles on.
A world-record deal for the France international, widely expected to cost United upwards of £100m, is close to being finalised.
The transfer could be publicly announced before United's Community Shield curtain-raiser against Leicester City on 7 August, according to the Daily Telegraph.
United are also reported to be keeping a close eye on Everton's negotiations with Manchester City over John Stones, even though the player does not fit the profile of the kind of defensive reinforcement that Mourinho wants.
City boss Pep Guardiola has confirmed that he is interested in signing the England defender, who is valued at £50m by the Toffees.
Mourinho has fielded Bailly, Daley Blind, Phil Jones, Marcos Rojo and Morgan Schneiderlin at centre-back in pre-season matches.
Chris Smalling, 26, is yet to make an appearance for United under Mourinho.
Bailly started alongside Blind at centre-back as the Red Devils played out a goalless draw with Everton in Wayne Rooney's testimonial at Old Trafford on 3 August.