Manchester United may bring forward plans to sign Gremio attacking midfielder Douglas Costa next month.

The teenager has been watched by United scout Jaap Stam this season and his agent has confirmed the interest of the European champs.

Gremio vice president Tulio Macedo admitted they were inviting offers for Douglas Costa for January's winter market: "We are willing to sell players. We need cash to buy players for the 2009 Libertadores."

Along with Douglas Costa, Macedo said Juventus target Felipe Mattioni and fellow defender Leo were also up for sale.