Walker ended up receiving an offer from a Scottish businessman to train there and moved to Scotland.

[7] In early 2018, Walker made the move to England where he fought for various promotions and added 3 more wins to his record and earned a spot on Dana White's Contender Series in August 2018.

[citation needed] Walker made his Dana White's Contender Series debut on August 11, 2018.

[13] The win earned Walker his second consecutive Performance of the Night bonus award.

[14] In a quick turnaround, Walker replaced an injured Ovince Saint Preux to face Misha Cirkunov on March 2, 2019, at UFC 235.

[20] Walker was initially scheduled to face Ryan Spann at UFC Fight Night 176 on September 5, 2020.

[21] However, Walker tested positive for COVID-19 and the bout was postponed to September 19, 2020, at UFC Fight Night 178.

[27] As the first bout of his new six-fight contract, Walker faced Jamahal Hill on February 19, 2022, in the main event at UFC Fight Night 201.

[38] Due to the controversial ending, the bout with Ankalaev was rebooked for the main event at UFC Fight Night 234 on January 13, 2024.

[43] However, Walker withdrew from the fight due to an injury and was replaced by promotional newcomer Billy Elekana.