Mickens attended Wayne High School, where he helped his team to two league titles and a 24-9 record. He posted in his career 205 tackles, 10 interceptions, 4 blocked field goals and one kickoff returned for a touchdown. He received All-Greater Western Ohio Conference honors twice. He also practiced track and field, winning the 300 metres hurdles state title as a junior and placing second on the 4 × 400 metres relay team at the state finals as a sophomore.
College career
Mickens accepted a football scholarship from the University of Cincinnati. As a freshman, he earned the starter right cornerback position during the preseason practices and went on to become an impact player, registering 51 tackles, 15 passes defensed and one interception. As a sophomore, he was moved to left cornerback, collecting 59 tackles, 15 passes deflected, 3 interceptions, one quarterback pressure, one forced fumble and one fumble recovery. He received All-American honors as a junior, after recording 53 tackles, 6 interceptions and 12 passes defensed. He combined with fellow cornerback DeAngelo Smith to register a total of 14 interceptions, the most by a cornerback duo in college football in 2007. He had 6 tackles and 2 interceptions, including one returned for a 45-yard touchdown against Southeast Missouri State University. He had 7 tackles, one interception and one fumble recovery against Marshall University. Mickens elected to return to school for his senior season, but suffered a left knee injury during a practice on November 20, 2008. He started 11 games at left cornerback, but missed the last 3 regular season games. He returned to play in the 2009 Orange Bowl, although he struggled in the contest. He finished the year with 70 tackles, 2 tackles for loss, 10 passes defensed and 4 interceptions. He had 14 tackles and 3 passes defensed against the University of Akron. He had 11 tackles and on pass defensed against West Virginia University. He left as the school's career leader in interceptions and interception return yards. He started 46 out of 47 games, while registering 233 tackles, 48 passes defensed, one sack, one forced fumble and 2 fumble recoveries.
Mickens was considered a possible first round talent, but ended up being selected in the seventh round of the 2009 NFL Draft by the Dallas Cowboys. He dropped because of concerns about the left knee injury he suffered in college, that caused him to run 4.53 at his Pro Day. He was waived on September 5, after showing a lack of speed and quickness. He was signed to the practice squad with the hope that he could return to his old form.
Tampa Bay Buccaneers
The Tampa Bay Buccaneers signed him from the Dallas Cowboys practice squad on November 2, 2009. He was declared inactive in three games, before being released on November 24.
Cincinnati Bengals
The Cincinnati Bengals signed him to their practice squad on November 30, 2009. He was released on April 15, 2010.
On May 27, 2010, Mickens signed with the Calgary Stampeders of the Canadian Football League. He was released on June 9 and decided to retire because of injury.
Coaching career
In 2011, he was a defensive assistant at the University of Cincinnati. In 2012, he was a defensive assistant at Indiana State University. In 2013, he became the cornerbacks coach at the University of Idaho. In 2014, he moved on to Bowling Green State University to be the cornerbacks coach. In 2014, he was named the cornerbacks coach at Bowling Green. In December 2017, it was announced that he was joining Kent State as the team's secondary coach. In January 2018, he was named the Cincinnati cornerbacks coach. In February 2020, he was hired as the cornerbacks' coach at the University of Notre Dame, reuniting with Brian Kelly, who has his head coach at the University of Cincinnati.
