On July 9, 2017, it was reported that Rush had been offered an NXT contract and that his signing was imminent. WWE confirmed the signing in August. Rush made his first televised appearance on the October 4 episode of NXT, where he was attacked by Velveteen Dream. On the October 11 episode of NXT, Rush was defeated by Dream in a match.] He would make one additional appearance on NXT television, losing a squash match to Lars Sullivan. He was then off television until April 2018.
In June 2018, Rush was moved to WWE's main roster as part of the cruiserweight division, appearing on 205 Live. Upon his debut, he went on a winning streak, defeating Noam Dar, Akira Tozawa and three jobbers. He suffered his first loss in a 5-way number one contendership match for the WWE Cruiserweight Championship, that was won by Tony Nese. He suffered his first pinfall loss to Cedric Alexander a few weeks later.
On the September 17 episode of Raw, Rush became the hype man and manager of Bobby Lashley and was responsible for turning Lashley heel when he encouraged him to attack Kevin Owens multiple times after their match on October 8. Rush then would later help Bobby Lashley capture his first Intercontinental Championship in a triple threat match against Seth Rollins and Dean Ambrose, when Rush distraced Rollins, allowing Lashley to spear Ambrose and pin him for the title.
Following the Royal Rumble, Rush and Lashley began feuding with Finn Bálor. His last match on 205 Live would be a number one contendership fatal four way on February 5, 2019, that was won by Akira Tozowa. Lashley's feud with Balor lead to a 2-on-1 handicap match at Elimination Chamber for Lashley's title, where Rush was ultimately pinned by Bálor, resulting in Lashley losing the Intercontinental Championship. After the match Lashley attacked Rush, leaving him laying in the ring. The next day, Rush and Lashley were defeated by Finn Balor and the debuting Ricochet. The next week, Rush unsuccessfully challenged Balor for the Intercontinental Championship. However, on the March 11 episode of Raw, Rush helped Lashley to regain the Intercontinental Championship from Balor. The following week, Braun Strowman and Balor defeated Lashley and Rush in a tag team match. Near the end of the match, Lashley fled the ring, leaving Rush to get pinned by Strowman. Following that, he did not wrestle for the company and stopped appearing alongside Lashley after WrestleMania 35 in April.
On September 18th edition of NXT, he made his televised return, defeating Oney Lorcan to earn #1 contendership for Drew Gulak's Cruiserweight title, in which he successfully captured the title (which was now renamed to NXT Cruiserweight Championship) for the first time in his WWE career on the October 9 episode on NXT. At Survivor Series, Rush successfully defended the title in an inter-brand triple threat match against Raw’s Akira Tozawa and SmackDown’s Kalisto. On the December 11 episode of NXT, he lost his title to Angel Garza, ending his reign at 63 days. On April 15, 2020, Rush was released from his WWE contract.