Stanley signed for Edinburgh in the Pro 14 after a successful trial for the remainder of the 2018-19 season, where he gained game time for partner club Watsonian in the Super 6. He extended his contract for a further season for the 2019-20 season. However, on 3 March 2020, Stanley left Edinburgh with immediate effect to sign for Gloucester in the Premiership Rugby. He made his debut as a replacement for Gloucester against local rivals Worcester Warriors on 15 August 2020 during the resumption of the 2019–20 Premiership Rugby season.