Almost a year ago the 6ft 2ins, 16 stone prop was looking forward to playing in the Super League grand final with Leeds only to be dropped by coach Tony Smith on the eve of the Old Trafford title decider.

With Smith having left Leeds, Thackray had high hopes for 2008, but after impressing in the pre-season games he was called in by new coach Brian McClennan and told he was surplus to requirements and could leave if he found another club.

Despite a dearth of quality forwards, no other Super League clubs expressed any interest in him and he found himself playing in National Two with Doncaster, a loan spell that was cut short by injury.

But then Hull, who themselves had released Thackray less than two years before because of concerns over his attitude, threw the 28-year-old a career lifeline by offering him terms until the end of the season.

Thackray made his second 'debut' for Hull against Catalans in late March and has played in every match since, including the four Challenge Cup ties the club won to book their place in Saturday's Wembley final against St Helens.

Unfortunately for Hull, Thackray was registered as their player after the first of two signings deadlines had elapsed and was ineligible for the fourth- and fifth-round victories over Rochdale and Widnes.

Many people expected Hull to be expelled from the competition, but with no precedent or clear guidelines in the sport's bylaws, the Rugby Football League allowed them to remain in the Challenge Cup and imposed a record £100,000 fine, £40,000 of which was suspended.

"It's been another rollercoaster ride for me," admitted Thackray. "There's been nothing straight forward about my career, but this season has been more bizarre than anything that's happened before.

"What happened in the earlier rounds is over and done with now as far as I'm concerned. Hull didn't make any attempt to cheat, they just didn't register me in time and the RFL didn't pick up on it. I hadn't played for Leeds this year and didn't think there'd be a problem. No one was more surprised than I was when Widnes raised the issue.

"When we drew Bradford in the quarter-final I didn't know at that stage whether we'd be thrown out and it was a very nervous time for me. With everything else that's gone wrong at Hull this season I would have hated to have been responsible for getting us expelled.

"It's been sorted out, but of course it's going to be brought up this weekend and, if we win, for years to come. It's a pain ,but I reckon it would be a price worth paying."

Hull were forced to call on Thackray in the absence of frontline props Ewan Dowes and Garreth Carvell and that he has kept his place following their return is as much a testament to his own contribution on the pitch as it is the injury woes that have continued to beset the East Yorkshire club.

He concedes that in the past he has not been as focused as he could have been and has allowed events off the field to distract him – in 2006 he had an acrimonious split with his long-time partner and in 2007 declared himself bankrupt after running up six-figure debts – but insists he is a reformed character.

Thackray also bears no grudges against Leeds or their former coach Smith, although he remains puzzled by the circumstances of his departure from Headingley.

"I hadn't fallen out with anyone, I hadn't missed training or been late or anything.

"A few years ago people used to say I had off-field problems and I suppose I did, but I've changed and grown up a lot. I wasn't a problem at Leeds and can't put my finger on why I had to leave.

"That's gone now and I'm really settled here at Hull. Hopefully I'm going to be here for some time to come.

"To play at Wembley is going to be a dream come true. Things have worked out for the best – Leeds aren't at Wembley, but we are."

Few people expect Hull to beat St Helens on Saturday, but, as Thackray is well aware, strange things often happen when you least expect them.