Born in Dallas, Texas, while his father, Jim Jeffcoat, played for the Dallas Cowboys, Jeffcoat attended Plano West Senior High School, where he was a two-time first-team all-state defensive end. Over his final three seasons, he recorded 259 tackles, 25.5 sacks, 56 TFL, 42 pressures, four PBU, three forced fumbles, two interceptions, two blocked kicks, and a touchdown. He was named a High SchoolAll-American by USA Today, Parade, and EA Sports. He was selected to play in the 2010 U.S. Army All-American Bowl. Regarded as a five-star recruit by Rivals.com, Jeffcoat was listed as the No. 1 strong-side, defensive end in the class of 2010.
College career
Jeffcoat attended the University of Texas at Austin from 2010 to 2013. Jeffcoat was named a 2010 Freshman All-American by The Sporting News. As a senior in 2013, he was a consensus All-American and won the Ted Hendricks Award in recognition of his contributions on the field.
Jeffcoat was originally predicted to be drafted somewhere in the middle rounds of the 2014 NFL Draft. However, neither he nor any other member of the Longhorns team was drafted that year, the first time since 1937 that no Longhorns were drafted. Jeffcoat signed with the Seattle Seahawks as an undrafted free agent. The Seahawks released him on August 25, 2014.
Washington Redskins
On September 2, 2014, Jeffcoat was signed to the practice squad of the Washington Redskins. He was promoted to the active roster on October 7, but was waived three days later. The Redskins re-signed him to their practice squad again on November 13. He was promoted again to the active roster on December 16. In the Week 16 win against the Philadelphia Eagles that removed them from playoff contention, Jeffcoat recorded his first career sack on quarterback Mark Sanchez. The following week, he had his first career start with Trent Murphy on injured reserve and recorded his first career interception, which came off Tony Romo, in the Week 17 loss to the Dallas Cowboys. On November 7, 2015, he was placed on the team's injured reserve. He was waived by the team on April 14, 2016.
Cleveland Browns
Jeffcoat was claimed off waivers by the Cleveland Browns on April 15, 2016. On August 1, 2016, Jeffcoat was waived by the Browns.
Jeffcoat was signed by the Winnipeg Blue Bombers on February 21, 2017. In 16 games played, Jeffcoat contributed 36 tackles, 7 sacks, 3 tackles on special teams, one interception, and a forced fumble. In Winnipeg's one postseason game, Jeffcoat had 5 tackles and a sack, but the Blue Bombers were defeated by Edmonton. 2018 saw Jeffcoat miss several games with injury, but he still put up a respectable 21 tackles, 5 sacks, and 2 forced fumbles. Jeffcoat also had a monster postseason, committing four sacks total in two games played, but a loss to Calgary in the Western Division final denied Jeffcoat and the Blue Bombers a trip to the 106th Grey Cup. After fulfilling his CFL rookie contract, Jeffcoat was eligible to become a free agent on February 12, 2019. Jeffcoat was pursued by interested NFL teams, and was brought in for a workout by the Cincinnati Bengals. However, Jeffcoat was signed to a two year contract extension with the Blue Bombers on January 21, 2019. Jeffcoat's 2019 season was almost identical to his 2018; he missed time with injury, played in the same number of games, had the same number of sacks and forced fumbles. In the 2019 Grey Cup, Jeffcoat had 4 tackles, 2 sacks and forced a fumble, which he recovered as the Blue Bombers went on to win 33-12.
