Barrett played college soccer for the UCLA Bruins from 2003 to 2004, earning accolades for his offensive prowess. He was selected as the third overall pick in the 2005 MLS SuperDraft by the Chicago Fire, marking the beginning of his professional career.
Throughout his thirteen-year MLS career, Barrett played for a number of clubs. His journey included stints with the Chicago Fire (2005–2008), Toronto FC (2008–2011), and the LA Galaxy (2011–2012), where he was part of the team that won the MLS Cup in 2012. He later went on to play for the New England Revolution (2013), San Jose Earthquakes (2014), and Real Salt Lake (2015–2016). He briefly returned to Real Salt Lake in 2017 before announcing his retirement.
On the international stage, Barrett represented the United States at various youth levels, including the U-20 and U-23 national teams. He officially retired from professional soccer in 2017.