The 25-year-old has been a free agent since November, following an unsuccessful spell with Brazilian club FC Bahia, with recent training stints at both Blackpool and Norwegian side Stabaek, under former national team manager Bob Bradley, ultimately failing to produce a contract.
He had previously experienced two largely underwhelming seasons in MLS with the Philadelphia Union before joining Bahia in April 2013 in a swap for Brazilian World Cup-winner Kleberson, appearing in just seven games until his November release.
Once widely considered a future star of world football, Adu began his professional career with D.C. United as a 14-year-old, signing a multi-million dollar contract as the first pick of the 2004 MLS SuperDraft, which made him the highest-paid star in the league at the time.
His arrival met with a vast amount of media hype, he was labelled ‘the next Pele’ by some, spending four seasons in the States between D.C. and Real Salt Lake, while also going on a two-week trial with Manchester United in November 2006.
Earning a $2 million move to Benfica the next summer, Adu's career would turn into an odyssey from this point forward, with a four-year spell in Europe seeing further stops in France, Greece and Turkey, until his return to MLS with the Union in August 2011.
With 17 international caps to his name, the playmaker last appeared for the USA in the 2011 Gold Cup, immediately prior to the hiring of Jurgen Klinsmann, with his AZ trial uniting him with current squad member Aron Johannsson and national team legend Ernie Stewart, the team’s technical director and a former teammate of his in MLS.
As the club where striker Jozy Altidore enjoyed one of the best seasons ever for an American in Europe, scoring 31 goals in 41 games during the 2012-13 campaign to earn a move to Sunderland, Adu will thus be hoping that the side’s history of success with his fellow countrymen can help revive his career.