Madrid  - European champions Barcelona have made a big offer for promising Valencia youngster Juan Mata, according to Spanish media reports on Friday.

According to the websites of AS, Marca and Sport, Barca have offered 20 million euros (28.77 million dollars) for the 21 year-old left winger.

Valencia president Manuel Llorente will consider the offer later on Friday.

Llorente - Valencia's fourth president within 18 months - made headlines in July by turning down big offers for striker David Villa from Barca and Real Madrid, claiming that Valencia's cashflow problems are not so serious as previously reported.

Llorente is working hard to open a credit line that would allow him to hold on to the team's stars and recommence work on Valencia's new stadium, work which was suspended in February due to the club's debts.

So far, the only player that Llorente has sold this summer has been defender Raul Albiol, to Real Madrid for around 15 million euros.

Mata, a product of Real's youth scheme, joined Valencia in 2007 and has scored 16 goals in 61 appearances. He was the star of the show in the 2008 King's Cup triumph, under coach Ronald Koeman.

He has played three times for Spain and was part of the Spanish squad at the recent Confederations Cup tournament in South Africa.

So far this summer Barca have only bought two players: striker Zlatan Ibrahimovic and left-back Maxwell, both from Inter Milan.

In addition to Mata, they are also interested in Shakhtar Donetsk defender Dymtro Chygrynskiy, after having loaned Martin Caceres out to Juventus. (dpa)