Patmon participated in football and track and field for the Vista Ridge High School Rangers. He played cornerback and wide receiver. He was named All-district first team his junior and senior years. Patmon also earned academic all-district honors and was a state qualifier in track.
Patmon played from 2010 to 2012 for the Kansas Jayhawks, where he was a three-year starter. He was redshirted in 2009. As a junior, he started 12 games and recorded 58 tackles (fourth on the team). He finished his Jayhawk career with 142 tackles, 11.5 tackles for loss, 22 passes defensed and 6 interceptions. He earned first-team Academic All-Big 12 honors in 2010 and 2012.
In 2013, he transferred to Oklahoma State University to play football, after finishing his junior season, completing his undergraduate studies and mentioning that the decision was "not by choice". During the season, he recorded 30 tackles (4 for loss), 9 passes defensed, one interception and one forced fumble.
After not being selected in the 2014 NFL Draft, he received a tryout invitation by the Dallas Cowboys for rookie-minicamp where he performed well enough to be signed as an undrafted free agent on May 21. In preseason he made the team over former fourth round draft choice B.W. Webb. He debuted on September 7, against the San Francisco 49ers.
As a rookie, he missed three games with knee and ankle injuries and was active for eleven. He was used in the nickel defense and his playing time increased during the team's final four games. On November 2, he scored his first touchdown against the Arizona Cardinals, after returning his first interception.
In 2015, he was named the team's nickel cornerback after having a strong training camp and Orlando Scandrick suffering a season ending knee injury. Patmon changed his number from 20 to 26. He was passed on the depth chart by Corey White in the fifth game of the season against the New England Patriots and was declared inactive for the next two weeks. He regained his role in the eighth game of the season against the Philadelphia Eagles, but was not able to make a noticeable difference in the team's defensive play. On December 15, he was waived to make room for cornerback Terrance Mitchell, finishing with 11 games played, 15 tackles and 6 passes defensed (at the time third on the team). The Cowboys offered him a chance to join their practice squad, but he decided to sign with a different team.
On December 17, 2015, Patmon was signed to the Miami Dolphins' practice squad. On December 26, he was promoted to the 53-man roster and appeared in 2 games during the season. On July 31, 2016, he was released.
On August 1, 2016, Patmon was claimed off waivers by the Tennessee Titans to improve the team's depth, after cornerbacks Brice McCain and Bennett Okotcha were injured. He was released by the team on August 28.
On October 20, 2016, Patmon was signed to the Kansas City Chiefs practice squad. He was released on November 2, and although he was re-signed to the practice squad on November 8, he was cut the next day.
On November 22, 2016, Patmon was signed to the Carolina Panthers' practice squad. He was signed to a reserve/future contract on January 2, 2017. He was waived on May 1, 2017.
On May 22, 2017, Patmon was signed by the Jacksonville Jaguars.