Manchester United have reportedly been left on alert after comments made by the agent of Real Madrid forward Gareth Bale.

The Wales international has come in for criticism from a number of quarters in recent months, and the player's representative Jonathan Barrett has moved to describe the club's fans as "a disgrace".

Reports have previously suggested that Bale has no interest in a return to the Premier League, but according to The Mirror, United are monitoring the situation.

Barrett has said that there have not been any talks regarding a potential exit from the Bernabeu, but the agent's comments will lead to further speculation about the 29-year-old's future.

Bale - who was jeered during El Clasico at the weekend - has netted 13 goals from 33 outings in all competitions this season.