Real Madrid defender Raphael Varane had reportedly emerged as a £100m target for Manchester United during the summer transfer window.
United will head into the new Premier League campaign having failed to bring in a new centre-back, despite being frequently linked with the likes of Toby Alderweireld, Harry Maguire and Jerome Boateng.
The hierarchy at the North-West giants were allegedly against paying what they considered to be over the odds for any additions, but according to The Sun, the club were prepared to spend big on Varane.
United would have allegedly deemed an offer of £100m as good value for money, with the France international only being 25 years of age and having the potential to play a leading role in the centre of the defence for a decade.
However, a move did not materialise and Mourinho must now work with the same central defensive setup as he did last season.
