Bale joined Real for a world record £85million this summer after a protracted transfer saga between Tottenham and the Spanish giants.
But the Welshman has had to contend with a difficult start to life in Madrid, after seeing a number of niggling injuries hinder his progress.
The Daily Express says according to reports United are keeping tabs on how the 24-year-old adapts to life in Madrid with view to a shock move for his services next year.
United did make a £100m bid for Bale in the summer but the former Spurs flyer had his heart set on playing for boyhood club Real.
New Old Trafford boss David Moyes is prepared to go back for Bale in 2014 though, although the Welsh international is intent on making his presence felt at the Bernabeu.
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