Rivers was selected by the New England Patriots in the third round (83rd overall) of the 2017 NFL draft.[11] During training camp, he suffered a torn ACL and was ruled out for the season.[12] He was officially placed on injured reserve on September 2, 2017.[13]
Rivers made his NFL debut in Week 3 of the 2018 season, against the Detroit Lions. In Week 17, he recorded his first career sack when he took down rookie quarterback Sam Darnold in a win against the New York Jets.[14] He played in his first career postseason game on January 13, 2019, in a win against the Los Angeles Chargers. Rivers helped the Patriots reach Super Bowl LIII, although he was inactive for it. The team defeated the Los Angeles Rams 13–3.[15] He played in 6 regular-season games that season, recording 2 solo tackles and 1 sack.
Rivers suffered a knee injury in Week 2 of the 2019 preseason, and was ruled out for the rest of the season. He was placed on injured reserve on August 31, 2019.[16][17]
Rivers made the 53-man roster coming out of 2020's shortened preseason. He was active in Week 1, against the Miami Dolphins, where he recorded his first sack since 2018 on quarterback Ryan Fitzpatrick. He was placed on the reserve/COVID-19 list by the Patriots on October 17, 2020,[18] but was activated on October 21.[19] On November 21, Rivers was released by the Patriots to make room on the roster.[20]
As a Patriot, he played in 14 regular-season games through nearly 4 seasons (being injured for 2 of those seasons), making six tackles with 2.5 sacks. Rivers also played in one postseason game.
On November 23, 2020, Rivers was claimed off waivers by the Los Angeles Rams.[21] As a Ram, he played in 2 regular-season games, as well as both postseason games, their postseason being cut short with a loss of 32–18 to the Green Bay Packers.[22]
On March 23, 2021, Rivers signed with the Houston Texans.[23] On August 31, he was released, but re-signed to the practice squad on September 1.[24][25] He was promoted to the active roster on November 24.[26] On December 9, the Texans signed Rivers to a two-year, $1 million deal.[27] The last game he played in for that season was on December 19 against the Jacksonville Jaguars, where he recorded his first sack since Week 1 of 2020 on quarterback Trevor Lawrence.[28] This was his only sack of the season, having played in only 5 consecutive games that season, beginning on November 21.
On August 30, 2022, Rivers was placed on injured reserve with a torn biceps tendon.[29] He was out for the entire season.
Rivers re-signed with the Texans on March 16, 2023.[30] On August 30, he was both released from the active roster and signed to the practice squad.[31] In a flurry of moves over the course of three weeks, Rivers was shifted between being promoted to the active roster,[32] being released,[33] and being re-signed to the practice squad, starting with his promotion to the active roster on September 21 and ending as a member of the practice squad on October 7.[34][35][36][37] He was released on November 1.[38]
On December 7, 2023, the Indianapolis Colts signed Rivers to their practice squad.[39] He was not signed to a reserve/future contract after the season and thus became a free agent upon the expiration of his practice squad contract.[40] He was re-signed on August 14, 2024.[41] Rivers was released on August 25.[42] He was re-signed to the practice squad on September 24.[43] Rivers was released on November 12 and re-signed to the practice squad one week later.[44][45] He was released on November 25.[46]