Premier League champions Manchester United are reportedly preparing a big-money bid in an attempt to prise Borussia Dortmund star Marco Reus away from the club in January.

According to The Times, United manager David Moyes dispatched assistants Steve Round and Jimmy Lumsden to Signal Iduna Park on Tuesday, when the Germany international scored and bagged an assist in the club's 3-1 victory over Napoli in the Champions League.

However, it is understood that the English giants will be hindered in their pursuit of the 24-year-old due to reports that Reus's £29m release clause cannot be triggered until 2015.

Reus, whose existing deal expires in 2017, is said to be rewarded for his form at Westfalensatadion by being offered a new contract - which would negate the reported buyout clause.

The former Borussia Monchengladbach starlet has hit nine goals in all competitions for the German giants so far this season.