Union's Adu to train with Spanish club

Philadelphia Union midfielder Freddy Adu will train with Spanish La Liga side Rayo Vallecano for two weeks.

Adu signed with the Union in August and played 11 games, including six starts. He had two goals and an assist. He will begin training Friday with Vallecano.

The 22-year-old Adu started his club career with D.C. United in MLS at 14, and later played with Real Salt Lake before moving to Europe.

He joined Portugal's Benfica in 2007, but made just 11 appearances during his stay, as he spent time on loan with Monaco in France, Belenenses in Portugal, Aris in Greece, and Rizespor in Turkey.

Adu left Benfica last summer to return to MLS, but the trial may open the door for a move back to Europe.

Philadelphia opens its 2012 MLS schedule March 12 at the Portland Timbers.