Sergi Roberto
Barcelona will reject all January approaches for Sergi Roberto. (Reuters)

Barcelona are bracing themselves for another bid from Manchester United in the January transfer window - this time for 21-year-old midfielder Sergi Roberto.

The Premier League champions still have another midfielder high on their priority list having failed with summer bids for Cesc Fabregas and Athletic Bilbao's Ander Herrera and have now turned to another Spaniard in La Masia product Roberto, according to Mundo Deportivo.

United are hoping to see a scenario similar to the one that saw Thiago Alcantara opt to leave the Nou Camp during the summer transfer window unfold over the next few months.

The Spain Under-21 international chose to leave the club for Bayern Munich after failing to get assurances of first team football from the club's hierarchy and United hope Barca's embarrassment of riches in midfield will leave Roberto in a similar predicament.

However, although the 21-year-old has made just three appearances for the Catalan giants this season - game time that amounted to less than 15 minutes on the pitch - El Mundo suggest he is unlikely to be swayed by an offer from David Moyes' side.

Roberto, who has represented Spain's Under-21's on seven occasions, was promoted to Barca's first team by Gerardo Martino during the summer and has been given assurances by the former Newell's Old Boys coach that he will receive opportunities in a starting berth as the season progresses.

El Mundo suggest a number of clubs including Tottenham Hotspur have attempted to take the midfielder on a season long loan, similarly as Everton did with exciting prospect Gerard Deulofeu.

But the club are not willing to allow Roberto to leave on a temporary or permanent basis, believing the midfielder is better suited to being around the current first team.

With Marouane Fellaini possibly ruled out for the next two months, United's own midfield options have taken another hit. The club failed with a transfer deadline day bid for Herrera and have been told by Athletic Bilbao president Josu Urrutia to forget about signing the 24-year-old when the transfer window reopens in January.