[15] Through January 2015, Mastiff worked couple matches on Xplosion, where he lost to Mandrews (formerly known as Mark Andrews) and Samoa Joe.

[18][19] Mastiff made his NXT UK debut on the first episode of the show which aired on 17 October, when he defeated Sid Scala.

[20] Mastiff, who was yet to be defeated on NXT UK, fought Eddie Dennis to a double disqualification on the 2 January 2019 episode of the show.

[22] On the 5 June episode of NXT UK, Mastiff competed in a Fatal four-way match against Joe Coffey, Jordan Devlin and Travis Banks to determine the #1 contender for the WWE United Kingdom Championship.

[24][25] On the 30 January 2020 episode of NXT UK, Mastiff lost a six-man tag team match with Mark Andrews and Flash Morgan Webster, against Imperium's Marcel Barthel, Fabian Aichner and Alexander Wolfe.