He played amateur rugby league for Skirlaugh before turning professional with his hometown club, Hull.

[5] Hull reached the 2006 Super League Grand final to be contested against St. Helens, and Washbrook played at loose forward in his side's 4–26 loss.

[6] In September 2011, he signed a three-year deal at Super League club Wakefield Trinity, following Hull Coach Richard Agar.

[8] On 13 August 2015 Hull re-signed Washbrook on a two-year deal, with coach Lee Radford saying he returns a better player than the last time he was at the club.

[citation needed] He played in the 2016 Challenge Cup Final victory over the Warrington Wolves at Wembley Stadium.