picked off Jacoby Brissett in overtime in a 16–13 victory over the Indianapolis Colts. The pick set the Cardinals up to win the game on a Phil Dawson field goal. Overall, Mathieu finished the 2017 season with 78 total tackles, two interceptions, one forced fumble and one sack. On March 14, 2018, Mathieu was released by the Cardinals after refusing to take a pay cut. Houston Texans On March 17, 2018, Mathieu signed a one-year contract with the Houston Texans worth $7 million. In his first game with the Texans, against the New England Patriots, Mathieu had one interception, recovered a fumble, and had five tackles. He finished the season with 89 combined tackles, three sacks, eight passes defensed and two interceptions. Kansas City Chiefs 2019 On March 14, 2019, Mathieu signed a three-year, $42 million contract with the Kansas City Chiefs. Overall, Mathieu finished the 2019 season with 75 total tackles, four interceptions, 12 passes defended, and two sacks. On February 2, 2020, Mathieu won Super Bowl LIV when the Chiefs defeated the San Francisco 49ers 31–20. 2020 In a Week 4 26–10 victory over the New England Patriots, Mathieu returned an interception 25 yards for a touchdown, his first defensive touchdown as a member of the Chiefs and the second in his career. In Week 13 against the Denver Broncos on Sunday Night Football, Mathieu intercepted two passes thrown by Drew Lock. His second interception of the game occurred late in the fourth quarter and secured a 22–16 win for the Chiefs. Overall, Mathieu finished the 2020 season with 62 total tackles, nine passes defended, one fumble recovery, and a career-high six interceptions. In the Divisional Round of the playoffs against the Cleveland Browns, Mathieu intercepted a pass thrown by Baker Mayfield during the 22–17 win. In Super Bowl LV against the Tampa Bay Buccaneers, Mathieu recorded three tackles during the 9–31 loss. During the game, Mathieu got in a verbal altercation with Buccaneers' quarterback Tom Brady and tweeted that Brady "called me something I won't repeat" after the game. Mathieu later removed the tweet. Brady was mic’d up during said altercation, but the NFL refused to release the audio. 2021 On September 1, 2021, Mathieu tested positive for COVID-19 and was placed on the COVID-19 reserve list. He was activated off the COVID-19 reserve list on September 11. However, the Chiefs put him on the inactive list