FRISCO, Texas -- The Dallas Cowboys will not pick up Leighton Vander Esch's fifth-year option for 2022, according to his agent, Ron Slavin, which will make the 2018 first-round pick an unrestricted free agent after the upcoming season.

Vander Esch's injury history is the biggest reason. He missed 13 games over the past two seasons, starting with a neck injury that required surgery in 2019 and cost him seven games. He missed six games in 2020 because of a broken collarbone. If the Cowboys had picked up the option, the $9.1 million would have been fully guaranteed.

Before officially deciding to decline the option, executive vice president Stephen Jones said during draft weekend that the team would still like to keep Vander Esch beyond 2021 if it did not add the fifth year, but it will depend on how he plays.

Vander Esch's best season came as a rookie, when he was named to the Pro Bowl after the Cowboys selected him No. 19 overall. He had a franchise-rookie-record 176 tackles in 2018, including 19 against the Philadelphia Eagles. He also had five quarterback pressures, six pass breakups and two interceptions.

Some teams were concerned about his health coming out of Boise State, but the Cowboys took the chance. However, he injured his neck in an awkward collision with a teammate on a tackle in 2019 and had surgery to alleviate a nerve issue. Then in last season's opener, he suffered a broken collarbone in the first quarter.

The Cowboys have linebacker Jaylon Smith under contract through 2025, but they can get out of his deal from a salary-cap perspective without much of an issue. In this year's NFL draft, the Cowboys selected linebacker Micah Parsons in the first round, but they believe his versatility will allow them to use all three players at the same time. The Cowboys also drafted LSU linebacker Jabril Cox in the fourth round.

Vander Esch is the third first-round pick not to have his option picked up by the Cowboys since the rookie pay system was put in place. Morris Claiborne, the 2012 first-round pick, signed a one-year deal with the Cowboys after the 2015 season, and 2017 first-rounder Taco Charlton was released in 2019.