Antonio Valencia
Valencia targeted by Galatasaray, reports suggest. (Reuters)

Galatasaray will test Manchester United's resolve with a €15m bid for Antonio Valencia when the January transfer window opens, reports in Turkey suggest.

The Turkish giants recently appointed Roberto Mancini their new manager and the former Manchester City boss already has his eye on a number of Premier League players, according to Turkish newspaper Fanatik.

The Ecuadorian international has not enjoyed the best of starts to the new season with him and fellow wide man Ashley Young both guilty of underperforming in the early stages of David Moyes' reign as United boss.

The Turkish publication suggests the emergence of Adnan Januzaj has left Valencia's first team role at the club under scrutiny with Mancini now ready to take advantage and strengthen the team he inherited from former Galatasaray boss Fatih Terim, who was sacked in September.

However, the report goes on to suggest that Galatasaray may face competition from Everton, who will attempt to convince United to use the 28-year-old in a part exchange deal for Leighton Baines.

Valencia, who signed for United in 2009 for a fee reported to be in the region on £16m, has been the preferred choice on the right flank for much of the season, starting four of the club's five opening games.

However, following the club's humiliating 4-1 defeat to Manchester City, a game in which he was far from United's only underperformer, Valencia found himself dropped from the starting line-up for the following league game against West Brom.

The winger was also omitted from Moyes' starting XI in the club's recent win over Sunderland, coming in as a substitute with 14 minutes remaining.

Following Januzaj's outstanding full debut against the Black Cats that was marked by two goals, the 18-year-old is likely to remain in the Moyes' plans. The Scot also awarded his other wing option Nani a new five year contract last month, a clear indication that the Portuguese international has a long-term future at the club.