Ellis felt his world had collapsed when he sustained a foot injury during the warm-up to the opening game of the season against Leeds back in February.
It was on the eve of the former Rhinos player's eagerly-awaited return to Super League from a hugely-successful four-year stint in Australia's NRL and, as Hull's newly-appointed captain, he was distraught.
His debut for the Black and Whites was delayed by three months but he has appeared in 14 of their last 15 matches and now has the chance to pick up a first Challenge Cup winners' medal as Hull take on Wigan at the national stadium.
"It just shows how things can turn around," Ellis said. "There is always something to look forward to, even though it doesn't seem like it at the time.
"I was really disappointed with that first game at Leeds. To start my new career at a new club in that manner, particularly with all the hype about coming back from Australia, was the lowest point of my career.
"It's fitting now that this week could potentially be the highest, all in one season."
Ellis has played important roles in Hull's Cup wins over Wakefield, Catalan Dragons and Warrington which has given them a chance to make history.
The Airlie Birds have famously never won at Wembley and Castleford-born Ellis lost there on his only appearance - for England against Australia in the 2011 Four Nations Series.
"I went to a few finals at the old Wembley, cheering for Castleford," he recalled. "My first recollection was from '84 when we beat Hull KR and Jamie Sandy kept running and scored in the corner.
"There are great memories, even when you go as a neutral. It's a great weekend for rugby league. They don't have anything like this in Australia. It's something rich in history in our country. They have their State of Origin and we have our Challenge Cup."
Ellis managed to reach the Cup final, as well as the Super League Grand Final, in his first season with Leeds in 2005 but that was during the time of the rebuilding of Wembley and the game took place at the Millennium Stadium.
That was a already disappointment to Ellis and it was compounded by a surprise defeat by his current club Hull.
"The thing with the Challenge Cup is that you just never know," he said. "In my first year at Leeds in 2005 I was spoilt with finals. I probably thought I was going to play there every year or every other year and I've never played in one since.
"It just shows that you can play with the best teams but with the concept of knockout competition can still never get there. It was a great occasion in 2005 but part of me was wanting to emulate my heroes and play at Wembley so to get this chance it pretty special.
"It's a boyhood dream for any rugby league player to lead a team out at Wembley. I'm honoured to do it at a great club like Hull FC as well. There have been some fantastic captains over the years and I'm privileged to be added to that list."
Despite upsetting the odds to win their previous two cup-ties, Hull will retain the underdog status at Wembley.
"And rightly so," Ellis said. "Wigan have been, up until recent weeks, the dominant team in the competition and they've played in a Challenge Cup final in the last couple of years.
"They've got some players who have played in big games - they have certainly more experience than us - so we've got our work cut out, we realise that. We've got a healthy respect for them but we've proved we can mix it with the best and we are confident we can go there and do a job."