Updated

The Philadelphia Union announced Friday that it has signed attacking midfielder Freddy Adu on a free transfer from Portuguese club Benfica.

The 22-year-old will be unveiled during a press conference at PPL Park on Friday at noon (ET). Per Major League Soccer and club policy, the terms of the acquisition will not be disclosed.

Adu first signed with the league as a 14-year-old and was selected by D.C. United in the 2004 MLS SuperDraft. He went on to play three seasons with United, making 87 appearances, scoring 11 goals, and earning MLS All-Star honors twice.

The United States international joined Real Salt Lake in 2007 before moving abroad to sign with Benfica. While contracted with the Portuguese club, Adu also spent time on loan with four different club teams.

The move reunites Adu with Union head coach Peter Nowak, who coached D.C. United from 2004-06 during Adu's tenure with the club.

Adu has been capped 17 times by the U.S. National Team and also holds the distinction of being the youngest player to suit up for the United States. He made his international debut at the age of 16 and 234 days.