Bale faces an uncertain future at Real Madrid following a disappointing campaign last term.
The Bernabeu faithful have expressed their disappointment with his performances and jeered him in last month’s draw against Valencia.
Real fans were also highly critical of his display in yesterday’s disappointing home draw with Levante.
Manchester United are long-term admirers of Bale.
Starsport understand Jose Mourinho was on alert to launch a swoop last month.
Reports in Spain suggest Real president Florentino Perez is open to selling Bale at the end of the season.
And the opportunity to leave the Champions League winners could appeal.
According to Don Balon, Bale is fed up of the criticism he receives from the club’s fans.
The Welsh wizard has reportedly told his representatives that he plans to leave if his situation does not improve over the course of the campaign.
Perez admitted earlier this week that Bale is ‘transferable’.
The Bernabeu bigwig told Spanish radio station Cadena SER: ”[As for Bale], he is one of the best players we have and we are very pleased with him.
"There were no offers for him and what [Jose] Mourinho said about him was just said in a complimentary way.
"Every player is transferable right now and we'll see what happens in a year, although I don't know what'll happen next year, just as nobody does."
Bale is under contract until 2022 after signing a six-year deal last October.
