This time last year he was playing for Wakefield Trinity Wildcats in the Qualifiers, with them having finished bottom of Super League.
Indeed, they only escaped relegation after beating Championship Bradford Bulls in a tense decider at Belle Vue.
However, former Hull team-mate Lee Radford re-signed him for his hometown club and the utility player is now chasing a treble of trophies.
Washbrook is set to play second-row off the bench in tomorrow’s Challenge Cup final for the Super League leaders against Warrington Wolves and he admitted: “It has been a bit of a turnaround.
“I was just saying to my dad last week after we beat Catalans to secure the top-four that it’s been a bit of a whirlwind year.
“Obviously, there was a chance of losing my job if we got beat in that ‘Million-Pound Game’ and then, 11 months later, we’re just one game away from the Grand Final and have a Challenge Cup final to look forward to as well.
“It has been a bit of a dream come true.”
Washbrook, who turns 31 next month, has been to Wembley before with Hull but on the losing side against St Helens seven years ago.
“I missed the 2005 Cup win in Cardiff as I was just young and had only played a couple of games that year,” he recalled.
“I managed to get in the Grand Final team the following year and then 2008 when we played Saints at Wembley so I have been there and experienced it.
“But, hopefully, this time will be a different result.”
Washbrook has proved a useful addition for Radford – he played 20 minutes at hooker in last week’s win – and has maintained his place in the squad despite stiff competition in his primary position of back-row.
With his versatility, he can also play half-back, loose-forward or even centre if called upon, which makes him a fine player to have among the replacements.
Twenty of his 26 appearances this time around have come off the bench and he has scored three tries in his first campaign back with the Black and Whites.
“I was coming to get my place in the team every week,” insisted the player, who left for Wakefield at the end of 2011 after 134 games during his first spell with the East Yorkshire club.
“Luckily for me, I managed to get my chance early and take it.
“I’ve only missed three games so far this year so it’s been a great year for me personally and, with the team, things could not have gone any better.”
The next few weeks will be definitive, though, as Hull seek to make the final crucial steps on all three fronts.
They have beaten Warrington – who have won the Cup three times under Tony Smith – on both occasions this term but each was a close encounter.
“They’re doing well in the league, up there with us, and we’ve had a couple of ding-dong battles this year so Saturday should be entertaining,” admitted Washbrook.