He played college football for the Virginia Tech Hokies, and was selected by the Kansas City Chiefs in the second round of the 2008 NFL draft.

[1] At Hargrave, he was teammates with Jonathan Hefney, Brian Soi, DJ Ware, and Justin Harper.

In 2004; he did not play in the season opener vs. Southern California, but made a spectacular interception for a 38-yard return the following week vs. Western Michigan.

Flowers returned to action in 2005, posting 20 tackles (13 solo) with four pass deflections, 1 1/2 stops behind the line of scrimmage, and an interception.

He earned All-American second-team and All-Atlantic Coast Conference first-team honors, leading the league with 21 passes defended, breaking up 18 throws and picking off three others.

In 2007, Flowers intercepted five passes and deflected nine others; he also ranked third on the team with 86 tackles (56 solo), including eight stops behind the line of scrimmage.

[9] He recorded his first two career interceptions against Brett Favre of the New York Jets on October 26, returning the 2nd one 91 yards for a touchdown.

Flowers finished the season with 69 tackles (62 solo), 1 forced fumble, 13 pass break-ups, 2 interceptions and a touchdown.

Despite playing nearly all the 2009 season with a hurt shoulder,[10] Flowers accumulated 65 tackles (58 solo), 2 forced fumbles, 23 pass break-ups, and 5 interceptions.

Flowers finished his first season in San Diego recording 52 total tackles (48 solo), going along with 3 interceptions, and 10 passes defended in 14 games played.