Arsenal and Man United are both interested in signing Sporting Lisbon midfielder William Carvalho

Carvalho's playing style has been likened to Patrick Vieira's. Photo: PA

Arsenal will rival Man United for Sporting Lisbon's William Carvalho after one of Arsene Wenger's chief scouts recommended the youngster.

David Moyes has been keeping tabs on the box-to-box midfielder for several months and Arsenal joined the race to sign him when they sent Francis Cagigao to Lisbon in December 2013.

Cagigao is the man who discovered Cesc Fabregas in Barcelona's academy and recommended Lionel Messi to Arsene Wenger at a young age, before work permit issues scuppered any potential approach.

He travelled to Lisbon on December 21st to watch Carvalho's man-of-the-match performance in Sporting's goalless league draw against Nacional.

The 21 year-old midfielder has been likened to Arsenal legend Patrick Vieira because of his unique ability to shield the ball and an incredible turn of pace.

He made an impressive senior bow for Portugal in their crucial World Cup qualifying play-off second leg against Sweden in November 2013, replacing Joao Moutinho after 70 minutes with the tie still hanging in the balance.

Carvalho is understood to have a £37.5m release clause in his contract, but unlike some of their Portuguese rivals, cash-strapped Sporting will be more inclined to accept a smaller offer for one of their most promising players.

Arsenal must fend off interest from Man United, who have already scouted Carvalho on a number of occasions this season, most recently in the 0-0 draw against Porto in the Portuguese Cup on December 29th.

Watch Carvalho in action below