Blaney began his career with Finn Harps, captaining their under-17 team and also playing for their under-19 team. He made his senior debut in the 2017 season, making 3 League of Ireland appearances. He signed a new contract for the 2018 season in December 2017.
Doncaster Rovers
He turned professional in January 2018 after signing a two-and-a-half-year contract with English club Doncaster Rovers in January 2018. He moved on loan to Tamworth in July 2018 for an intended six months. He returned sooner and then moved on loan to Grantham Town in October 2018 for a month, making four appearances in all competitions. Blaney signed for Blyth Spartans on loan in February 2020. He was released by Doncaster at the end of the 2019–20 season.