Will Real Madrid sell out-of-form Bale to Manchester United?

Gareth Bale may have been warned by his new employers about how fickle the Real Madrid fans can be when he signed for the Spanish giants for a world record fee in 2013.

Just how fickle is now painfully clear to the Wales winger, who has become a target for supporters angry with Real's recent slump and has been whistled along with captain and goalkeeper Iker Casillas in recent outings at the Bernabeu.

Bale has not scored for the European champions in nine matches since he converted a penalty against Cordoba on January 24 and is struggling to shake off a perception that he neglects his defensive duties and sometimes selfishly opts to shoot himself when a team mate is better placed.

That Bale had a successful debut season in Spain, scoring the winning goal against Barcelona in the King's Cup final and netting in the Champions League showpiece against Atletico Madrid, has quickly been forgotten.

While it is unfair to blame Bale for all of Real's recent woes, it cannot be denied that he appears to be struggling for form and confidence.

His travails have even prompted speculation he could be sold, with English Premier League side Manchester United said to be interested.

The 25-year-old, who barely made an impact in Tuesday's 4-3 Champions League reverse at home to Schalke 04, has a chance to set things right when second-placed Real host Levante in La Liga on Sunday.

By the time the game kicks off, they could find themselves four points behind leaders Barcelona.

Barca leapfrogged their great rivals, who they host for the 'Clasico' on March 22, into top spot last weekend and play at Eibar on Saturday.

Real centre back Pepe defended Bale, who he described as "shy", in an interview with Spanish radio on Thursday.

"Ball hog? A forward lives on goals," the Portugal international said.

"When he gets into a position to score it's the instinct of the killer. If you put me in front of the goal I will shoot."

Champions Atletico Madrid, six points behind Real in third, are looking to get back to winning ways after draws against Sevilla and Valencia when they play at Espanyol on Saturday.

Fourth-placed Valencia can climb above Atletico if they avoid defeat at home to Deportivo La Coruna on Friday.