His international exposure earned him a scholarship to play for the University of Wyoming. As a freshman, he played as an outside linebacker in 10 games, before being moved to free safety during the latter part of the season. The next year, he was moved to strong safety, finishing with 11 games played, 32 tackles and a forced fumble. After earning the starting strongside linebacker position as a junior, he had a break-out season with 101 tackles, one sack, two forced fumbles and two passes defensed. In his last year, he was playing strongside linebacker in the base defense, middle linebacker in the nickel defense, and was a core special teams player. He was also leading the team in multiple defensive categories, before suffering a season-ending torn ACL in the seventh game against San Jose State University, finishing with 59 tackles, two sacks, two forced fumbles, and five passes defensed. He was named to the Academic All-Conference team in three-straight seasons.
Nzeocha was drafted by the Dallas Cowboys in the seventh round of the 2015 NFL Draft. The San Diego Chargers previously traded this pick to Dallas in exchange for Sean Lissemore. Due to his limited football experience, Nzeocha was targeted primarily because of his athletic ability. Entering the league as a 25-year-old rookie, he missed the entire preseason while recovering from a knee injury he suffered in college. Nzeocha began the regular season on the Reserve/Non-Football injury list and was activated until November 18. He only played in two games and was declared inactive for five. In 2016, Nzeocha was used at middle linebacker during the preseason, posting an interception against the Los Angeles Rams. He suffered a strained Achilles tendon in the second game against the Miami Dolphins, which not only forced him to miss the rest of the preseason but also the first 4 games of the regular season. Nzeocha played in five games mainly on special teams and was declared inactive in seven contests. In 2017, Nzeocha was the backup of middle linebacker Anthony Hitchens during organized team activities. On June 6, Nzeocha had his knee scoped, which delayed the start of his training camp. On September 3, he was released after the team acquired linebacker Jayrone Elliott in a trade and was re-signed to the practice squad.
On September 25, 2017, Nzeocha was signed by the San Francisco 49ers off the Cowboys' practice squad. He appeared in 10 games and had 4 special teams tackles. On January 26, 2018, Nzeocha re-signed with the 49ers. On March 15, 2019, Nzeocha signed a three-year contract extension with the 49ers. During the season-opener against the Tampa Bay Buccaneers, Nzeocha intercepted Jameis Winston once in the 31-17 victory. The 49ers reached Super Bowl LIV but they lost to the Kansas City Chiefs by a score of 31-20.
Personal life
Nzeocha's brother, Eric Nzeocha was a linebacker for the Tampa Bay Buccaneers and is a part of their practice squad. He is half Nigerian.
