Gratton was born in Rotherham and joined his boyhood club Rotherham United at the age of nine.[2] His first experience of first-team football came in January 2020, when he joined Scarborough Athletic on a youth loan.[3] A cruciate injury in early February kept him on the sidelines for a year, returning in February 2021.[4] In August 2021 he joined Guiseley on loan, returning in January 2022.[5][6] During this loan spell, he was given permission to be part of the Rotherham United squad for the EFL Trophy, and made his club debut as a substitute in the 6–0 win against Doncaster Rovers on 7 September 2021.[7] He joined Farsley Celtic on loan in February 2022, helping them avoid relegation.[8] Gratton was released by Rotherham at the end of the 2021–22 season.[9]
Following his release from Rotherham United, Gratton returned to Farsley Celtic on a permanent basis. In October 2022, he departed to join NPL Premier Division side Belper Town.[10]
Following a season with Whitby Town, he returned to Belper Town in August 2024.[11] The following month however, he joined Worksop Town having trained with the club in the prior pre-season.[12]