Davies signed his first professional contract with Swedish Allsvenskan club Hammarby IF in December 2006 before joining Sochaux in July 2009.

[2] He attended the Brooks School in North Andover, Massachusetts and graduated in 2004 alongside fellow professional Mike Fucito.

He was a well-established professional prospect, and was expected to be a very high MLS draft pick[7] had he chosen to accept the Generation Adidas contract that he was offered.

Davies credits both his coach, Tony Gustavsson, and Uruguayan star and former Hammarby teammate Sebastián Eguren with guiding his work ethic and attitude through his struggles.

[4][10] As a result of his strong performance in 2008 there were many rumors regarding his transfer to a larger club elsewhere in Europe, but ultimately nothing materialized, and Davies returned to Hammarby.

[14][15] On April 26, 2010, Davies returned to full training with his club[16] and was finally placed in the gameday roster for the December 19 match against Bordeaux.

The win put United into tenth place in the standings, the final playoff spot, just above the New York Red Bulls.

[32] Davies played ten games, mostly as a substitute, for the United States U-20 men's national soccer team, but did not make the roster for the 2005 FIFA World Youth Championship.

He led the team to the final where he scored a hat trick, making him the MVP of the competition and giving the U.S. its first Milk Cup success.

[36][37] He made his debut for the senior national team on June 2, 2007, as a substitute in a 4–1 friendly victory over China in San Jose, California.

On October 15, 2008, he scored his first national team goal in a 2–1 loss to Trinidad and Tobago during the third round of CONCACAF qualifying for the 2010 FIFA World Cup.

[14][15][39] In an interview with ESPN's Jeremy Schaap on December 4, Davies said that he expected to be running by March and would be fit to play at the World Cup.

[41] Davies returned to France to complete his rehabilitation with his club on February 17, 2010, with plans to commence full team training within a month.

[44] On May 11, it was announced by coach Bob Bradley that Davies would not be on the preliminary national team roster for the 2010 FIFA World Cup,[45] as Sochaux had not cleared him medically.

[46] Two years after the crash Davies filed a $20 million lawsuit against Das Enterprises, which operates the Shadow Room, and Red Bull North America, which hosted the private event at which alcohol was served.

[47] The parents of the woman killed in the crash also filed suit against the nightclub owner and Red Bull in U.S. District Court in Alexandria, Virginia.