[4] An undefeated run through the 2017 County Championship campaign saw Blackrock qualify for the final, with Cashman's side ultimately facing a four-point defeat by Imokilly.
[5] After a three-year absence Blackrock qualified for the 2020 final, with Cashman claiming a winners' medal after the 4–26 to 4-18 extra-time win over Glen Rovers.
He made his first appearance for the team when he lined out at left wing-back in a ten-point semi-final defeat by Waterford.
[citation needed] In October 2015, Cashman was drafted onto the Cork senior panel by team manager Kieran Kingston in advance of the pre-season 2016 Munster League.
[citation needed] Success at club level earned Cashman a recall to the Cork senior team prior to the start of the 2021 National League.