Flowers was born in Independence, Missouri. He attended high school at Millennium High School in Goodyear, Arizona, where he played running back, wide receiver, and free safety. He first played in 2007 as a sophomore, tallying 76 tackles, an interception and a fumble recovery. The following season, he played both on offense and defense, rushing for 932 yards and 8 touchdowns, as well as recording 6 receptions for 106 yards. He had 87 tackles on defense, as well as a sack, three interceptions, and another fumble recovery. He played in the U.S. Army All-American Bowl in January 2010.
College career
Flowers attracted interest from several colleges, notably Notre Dame, USC, UCLA, Arizona State University, and the University of Arizona, where he was recruited by Tim Kish. Flowers signed his letter of intent on January 9, 2010. Flowers played sparsely during the 2010 season, recording 11 tackles in 13 games, most of which came on special teams. Flowers moved into the starting free safety position before the 2011 season. He played in all 13 games in the 2011 season, and recorded 68 tackles, as well as 3 passes defended and an interception. Flowers transferred to outside linebacker during 2012 training camp. Flowers transitioned well, and maintained relatively the same production that he had during his sophomore season. He finished the 2012 season with 100 tackles, 5.5 sacks, three interceptions, six passes defended, and three forced fumbles, one of which he recovered. Flowers was named the Pac-12 Defensive Player of the Week after Arizona's 39-35 win over USC, where he intercepted two passes and recorded a fumble. In the 2012 New Mexico Bowl against Nevada, a 49-48 Arizona win, Flowers recovered a key onside kick that helped Arizona take a 1-point lead with 19 seconds to go. He then intercepted Nevada quarterback Cody Fajardo on the next play, sealing an Arizona victory. For his performance, he was named the defensive most valuable player. Flowers rounded out his college career in 2013, in which he recorded 94 tackles, 1 sack and 1 interception, which he returned for a touchdown.
Professional career
Cincinnati Bengals
Flowers was drafted by the Bengals in the sixth round with the 212th overall selection in the 2014 NFL Draft. He played in all 16 regular-season games as a rookie totaling eight tackles and one pass defended. Flowers suffered a shoulder injury in the final preseason game in 2015 and was placed on injured reserve, missing the entire 2015 season. In 2016, Flowers final year with the Bengals, he again played in all 16 regular season games, and recorded eight solo tackles, and one fumble recovery.
On August 29, 2017, Flowers was traded to the New England Patriots for a 2018 seventh round pick. Following injuries to Dont'a Hightower and Kyle Van Noy, Flowers saw his defensive snaps increase throughout the season after only being a core special teams player throughout his career. In Week 16, in his second start of the season, Flowers recorded a team-high 10 tackles and 2.5 sacks, in a 37-16 win over the Buffalo Bills. Flowers finished the season with 32 tackles and 3.5 sacks. In the playoffs, New England defeated both the Tennessee Titans and Jacksonville Jaguars to reach Super Bowl LII, but lost 33–41 to the Philadelphia Eagles with Flowers recording 1 tackle in the Super Bowl. On March 22, 2018, Flowers signed a one-year deal to remain with the Patriots. On September 1, 2018, he was released by the Patriots.
Detroit Lions
On September 3, 2018, Flowers signed with the Detroit Lions. He was released by the Lions on October 10,
