And Bale is now tipped to be more open than ever to finding a way to end his troubles in the Spanish capital.
Tottenham is negotiating a deal with the La Liga champion to re-sign Bale, who is "keen" on joining the English club as well, David Ornstein of The Athletic reported.
Tottenham, however, have the additional emotional pull for the player they signed as a 17-year-old from Southampton in 2007 and helped develop into one of the world's best players.
Madrid did not want to let go of Reguilon entirely.
Nevertheless, the winger's agent Jonathan Barnett stated playing in north London once again would be his client's preferred option.
Bale has won four Champions League titles with Real, but he has a reputation for uninterestedness as well as poor fitness.
Ole Gunnar Solskjaer has endured a frustrating transfer window so far as he's only managed to sign midfielder Donny van de Beek from Ajax having struggled to secure deals for his other key transfer targets.
Bale's salary is perhaps the biggest hurdle for Spurs to overcome, and he still has two years left on his contract which is thought to be worth around £600,000 per week.
Jose Mourinho has Ryan Sessegnon and Ben Davies as his options at left-back but it seems he's not pleased.
After losing their opening game of the Premier League season against Everton on Sunday, Tottenham could do with the morale-boost that would come from signing Bale.
Meanwhile, United are continuing negotiations with Madrid over full-back Sergio Reguilon, but will not match the Spanish giants £27m asking price.
Bale's team-mate, left-back Sergio Reguilon, has been linked to both United and Spurs.
Sources added that United have not yet agreed a fee for Reguilon and were hopeful they could drive down the price based on the player's desire to join them, but Spurs' concrete interest has complicated their pursuit.