tackle and made his first career sack on Ben Roethlisberger during their 30–27 loss. The following week, he earned the first start of his career against the New Orleans Saints, after starting right outside linebacker Barkevious Mingo was unable to play due to a shoulder injury. He went on to finish the game with four combined tackles as the Browns won 26–24. On October 19, 2014, Kirksey recorded a season-high nine combined tackles as the Browns lost 24–6 at the Jacksonville Jaguars. Kirksey started over Craig Robertson during a Week 11 matchup against the Houston Texans and tied his season-high of nine combined tackles in Cleveland's 23–7 loss. He started from Weeks 12–15 after Karlos Dansby suffered a knee injury during the loss to Houston. He finished his rookie season with 81 combined tackles (47 solo), two sacks, two pass deflections, and a forced fumble in eight starts, 16 games, and 343 defensive snaps. 2015 Kirksey continued to compete for the starting inside linebacker role against Robertson throughout training camp. He started the regular season as the backup inside linebacker behind Craig Robertson. On October 4, 2015, Kirksey earned his first start of the season after Craig Robertson suffered an ankle injury. He went on to collect five combined tackles and sacked San Diego Chargers' quarterback Philip Rivers, in Cleveland's 30–27 loss at San Diego. He started the next four games at inside linebacker (Weeks 4–7) in place of Robertson. In Week 6, he recorded a season-high nine combined tackles as the Browns lost 26–23 to the Denver Broncos. On November 15, 2015, Kirksey collected a combined four tackles and sacked Steelers' quarterback Ben Roethlisberger during a 30–9 loss at the Pittsburgh Steelers. He finished the season with 63 combined tackles (40 solo), 3.5 sacks, and a pass deflection in 16 games and five starts. 2016 Kirksey was slated to be the starting inside linebacker after Craig Robertson departed during free agency to the New Orleans Saints. New head coach Hue Jackson named Kirksey the starting right inside linebacker, alongside Demario Davis, to start the season. He started the Cleveland Browns' season-opener at the Philadelphia Eagles and recorded six combined tackles and sacked Carson Wentz during 29–10 loss. On October 9, 2016, Kirksey collected a season-high 16 combined tackles in the Browns' 33–13 loss to the New England Patriots. During a Week 10 contest at the Baltimore Ravens, he made