In 2015 he was linked with English club Manchester City.[3] In April 2018 he was linked with a transfer to Scottish club Celtic,[7] and he also trialled with Scottish club Rangers at the end of the 2017–18 season.[8]
In June 2018 he signed a two-year contract with English Bradford City.[3][8] He said the club's youth player development appealed to him.[9] In January 2019 he was linked with a transfer away from the club, back to Sweden.[10] He later left the club by mutual consent.[11] Later that month he signed for Swedish club Östersund.[12]
In January 2021, he signed for 2. Bundesliga side Darmstadt 98 for an undisclosed fee on a contract until 2024.[13] On 12 May 2024, the club announced that Isherwood would be one of several players who would leave the club at the end of the 2023–24 season.[14]
International career
Isherwood represented Sweden at youth international levels from under-17 to under-21.[15] He is also eligible to represent England.[3]