The versatile player has started his celebrations with a raft of events and will hold his benefit game against former club Wakefield Trinity – in tandem with their captain Danny Kirmond – at Belle Vue on January 13.
But Washbrook is showing no signs of slowing down and maintains he is ready to demonstrate he can still be a big, crucial part of his hometown club’s plans, despite nearing the twilight of his fine career.
Hull’s squad numbers have seen him drop from No 17 to No 30 which could hint that the 33 year-old will play less of a role in the season ahead.
But, he told The Yorkshire Post: “A number’s just a number. I wore number 30 in 2016 and played nearly every game, including our Wembley win.
“I’ve not talked to Radders yet about exactly what role I’ll be playing but as the season gets closer and we do more team stuff in training I’m sure we will.
“And it’s up to me; it’s not up to him just to pick me because I’ve played a certain amount of games. It’s up to me to prove I’m worthwhile being picked because I add value to the team.
“That’s what I intend on doing.”
Moreover, Washbrook – who filled in a lot at hooker last term as well as his more customary back-row position – has unfinished business.
He is the only survivor of Hull’s Grand Final team that lost out to St Helens in 2006 (admittedly Radford, Richard Horne and Kirk Yeaman are all on the Black and Whites coaching staff), still their only appearance in the showpiece event.
They have never been back to Old Trafford since and the last time they won the league title was as far back as 1983.
“It’s definitely something I want to achieve,” said Washbrook, who did play in both Challenge Cup final triumphs in 2016 and 2017. “When people talk about their highlights, those who have won it say the Grand Final is the pinnacle.
“It means you are the best team over the full year.
“Winning at Wembley was brilliant, to go on a cup run like that, but winning at Old Trafford is what we all want now.”
If Hull are to succeed in that regard, undoubtedly they have some work to do.
Their end to the last campaign was utterly abysmal, suffering a club record of 11 successive defeats that left them drained, demoralised and under mounting pressure.
Of course, there was mitigation with a series of injuries to a large number of the squad and a Super 8s campaign that held little appeal given they had fallen way off the title-chasing pace by the time it arrived.
Understandably, Hull owner Adam Pearson was furious and threatened changes in personnel ahead of 2019 although, as yet, there have been no major departures.
Yet it is largely the same squad that enjoyed those famous back-to-back Wembley victories so does Washbrook believe, with a fully-fit squad, that they can actually still challenge at the top end of the standings?
“Definitely,” he insisted. “When we had a full team we didn’t play too badly; we were at the right end of the table.
“We certainly proved at the beginning of the year we could be up there and pretty much nothing has changed (squad-wise) since.
“But we know how poor we were at the end of last season. We want to right a few wrongs, not just for ourselves but the fans and the owner, who made his thoughts very public at the time.
“He’s every right to do that and I think we need to prove to him that we are a better team than what we showed during that spell. We have to.”
Meanwhile, Washbrook revealed there was one point briefly when he considered calling it quits.
“At the beginning of last season I did start thinking about it,” said the player, who has made more than 200 Hull appearances spread either side of his 2012-15 stint at Trinity.
“There was a slight consideration about retiring. But once I started playing again and was playing well, that disappeared.
“I’m looking forward to this next season now. After that, I’m not sure. I’ve not thought too much about what I’ll do afterwards but I’m currently trying to get something sorted, possibly at the club. But we’ll see.”
Elsewhere, former Hull chief executive James Rule has announced he will quit the same role at Widnes Vikings at the end of 2019.
Rule, with Widnes for six years, saw the club relegated in September and says it will be “the right time to step aside.”
Leeds Rhinos chief executive Gary Hetherington has ruled out a move for St George-Illawarra captain Gareth Widdop as they already have two ‘marquee’ players but he hopes another Super League club will sign the Halifax-born England stand-off in 2020.