Guy attended La Costa Canyon High School where he was named MVP for its soccer team twice.

After scoring a goal in one of three Combine friendly matches, Guy was drafted in the 2nd round (22nd overall pick) of the 2007 MLS SuperDraft by FC Dallas.

He made his League of Ireland debut for the Irish club on April 6, 2007, coming on as a substitute in the 83rd minute of a 1–0 win over Galway United.

On August 4, 2010, Guy and Joey N'do were the only two foreign players selected for a League of Ireland XI in a friendly match against Manchester United.

[6][14] Upon his return to the US, Guy had a short stint with the San Diego Flash of the National Premier Soccer League, and trialled with the Portland Timbers and FC Dallas.

[15][9] After injury to right-winger Sainey Nyassi, a trial and recommendation from San Diego Flash head coach Warren Barton lead New England Revolution Head-Coach Steve Nicol to sign Guy mid-season on June 9, 2011.

[16][17] Guy made his Revolution debut on June 18, 2011, coming on as a 71st minute substitute for Chris Tierney in a 1-1 draw against the Chicago Fire.

[19] On September 25, 2011, Guy would contribute his first goals for the side scoring a late brace against Chicago Fire in a 3-2 loss.

During his two years at New England Revolution he showcased versatility by playing in nearly every position on the field, though he didn't spend an extended period in any single role.

Guy credits this period as a key influence on his understanding of football tactics, helping him develop a better grasp of positioning, roles, and responsibilities, skills he believes have enhanced his coaching ability while also being cited as a natural leader.

[27][28][2][3] Guy was born in Carlsbad, San Diego County, California to Jesse Anderson Lujan, a former Guam Legislature senator and KUAM-FM talkshow host,[29] and Sandra Guy-Willoughby.

[6] Guy attended La Costa Canyon High School, where he was an honor student receiving honorary academic captain for senior year by The San Diego Union-Tribune.