Spanish media outlet OK Diario is reporting that the Manchester United boss has held discussions with the Real Madrid forward over a potential move to the Spanish capital.
The same article states that the Manchester United manager has made the promise to the 29-year-old as Bale looks to end Lionel Messi and Cristiano Ronaldo’s dominance of the Ballon d’Or over the past decade.
According to the same story, Bale is reluctant to make a decision until Ronaldo’s future at the Champions League winner has been resolved at The Bernabeu.
Bale scored twice from the bench to help Real Madrid ease to a 3-1 win against Premier League side Liverpool FC in the Champions League final in Kiev last month.
The Red Devils have been regularly linked with a move to sign the Welsh forward over the past few transfer windows.
Manchester United finished in second place in the Premier League table but ended up 19 points adrift of champions Manchester City.
The Red Devils lost 1-0 to Chelsea FC in the FA Cup final at Wembley.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news