The Texans issued an official statement about the decision Wednesday:
"Johnathan has been a consummate professional, team captain and one of the leaders of our defense for the past nine years. It is rare for a player to sustain such a high level of play for over a decade and that says so much about him and his dedication to the game. He is an exceptional teammate, mentor, husband and father. His impact on and off the field makes him quite possibly the most celebrated free agent signing in franchise history. The entire Houston Texans organization thanks Johnathan for the contributions he made to our team and the Houston community. We wish him and his family all the best as he pursues free agency."
Joseph later took to social media to address his tenure in Houston:
Joseph was scheduled to become a free agent after completing a two-year, $10 million contract signed in March 2018.
Originally signed by the Texans in July 2011, Joseph has been a staple of Houston's defense over the past nine seasons. He made the Pro Bowl in each of his first two seasons with the team.
The addition of Joseph to Houston's secondary helped ignite the franchise into a consistent playoff contender for most of the previous decade. The Texans had the NFL's worst secondary in 2010, when they allowed a league-high 267.5 passing yards per game and 33 scores through the air.
With Joseph, as well as the hire of defensive coordinator Wade Phillips, the Texans had the No. 3 in pass defense in 2011. They won the AFC South and made the playoffs for the first time in franchise history that season.
In March 2018, John McClain of the Houston Chronicle named Joseph as the best free-agent signing in Texans history.
In 133 games with the Texans, Joseph has recorded 482 combined tackles, 118 pass breakups and 17 interceptions.