Red Devils legend Gary Neville was among those urging his former club to sign a new centre-back during the recent summer transfer window.
United’s defence in fact performed well during the second-half of the 2019-20 season, conceding only seven goals and keeping nine clean sheets during an unbeaten run of 14 games as the club finished third in the Premier League.
Ed Woodward was still expected to sign a new centre back over the summer, however, with United conceding three goals against Crystal Palace, two against Brighton and six in their embarrassing defeat to Tottenham.
The club spent £80million on England international Harry Maguire last summer but there have been question marks over his partnership with Victor Lindelof, while Eric Bailly has also often struggled when called upon.
The Athletic say Manchester United were made aware of Burnley’s James Tarkowski over the summer and also looked at France international Upamecano and Senegal star Koulibaly.
However, a deal never materialised and the Premier League giants will instead make singing a central defender their priority for the summer of 2021.
Man United face missing out on transfer targets Upamecano and Varane if they fail to qualify for the Champions League, with both players set on playing in Europe’s top competition.
While United failed to sign a new central defender, they were also unable to offload Marcos Rojo and Phil Jones, who have both been left out of Solskjaer’s Champions League squad.
He wrote on Twitter: ‘It’s appalling that in this market which is probably the easiest in PL history to get transfers done that United haven’t done more yet!
‘They must get a CB , LB and forward! The others are managing to get things over the line why not Manchester United!’