William Carvalho
Carvalho scouted by both Arsenal and United. (Reuters)Reuters

Arsenal may be preparing to join the race to sign Sporting Lisbon midfielder William Carvalho having dispatched scouts to watch over the Manchester United target.

Portuguese newspaper A Bola report that the Gunners sent respected scout Francis Cagigal to the Estadio Jose Alvalade on Saturday night to watch over the 21-year-old midfielder.

Although Sporting were unable to stretch their lead at the summit of the Portuguese Liga as they laboured to a 0-0 draw with Nacional de Madeira, A Bola suggest Cagigal was greatly impressed with Carvalho's powerful performance in midfield.

He was reportedly joined in the stands by Manchester United scouts who had previousy travelled to the Portuguese capital six times prior to the weekend to cast an eye over the highly rated youngster who has been capped once at full international level by Portugal.

Carvalho, who has enjoyed a breakthrough campaign with a string of virtuoso performances in the heart of midfield, currently has a release clause of €45m, but it is understood that Sporting may be willing to listen to offers less than that.

While the return of Darren Fletcher to the first team squad has been a timely boost for David Moyes, the centre of midfield remains the area that club are strongly expected to strengthen in January.

With attempts to revive a move for Athletic Bilbao midfielder Ander Herrera now looking very unlikely and Atletico Madrid starlet Koke showing little desire to leave the Vicente Calderon, the number of attainable targets on the market for the Premier League champions appears to be dropping.

Wary of the perils that often befall clubs during the January transfer period, Moyes anticipates it may be difficult for the club to get hold of their primary targets at this stage of the season.

"We will look (at targets)," Moyes told reporters on Monday. "But I wouldn't turn around and say that I am massively sure we will get them.

"Because a lot of the players we would be interested in wouldn't be available for us in that month of January. But we'll certainly be looking."