Three weeks ago Deeney scored a dramatic injury-time winner against Leicester to seal Watford's passage to the showdown. The elation that followed that strike could not have been more different to the feeling that Deeney was experiencing 12 months earlier when he was awaiting trial for affray following a street brawl in Birmingham.
Deeney's worst fears came true in June 2012 when he was convicted and sentenced for 10 months, but he has since turned his life around, scoring 20 goals to lead Watford to the verge of a place in the Barclays Premier League.
The 24-year-old celebrated wildly with his family following the winner against the Foxes at Vicarage Road and he has repaid them for standing by him while he was in prison by picking up most of the tab for nearly 100 tickets for Monday's game.
"I've had requests for 96," the striker said. "I've got everybody - my nan, mum, brother, sister. I had to re-write the list because I forgot one or two, but I got (one for) everybody, so it's going to be a good day - as long as we win.
"I'm still selling blood to pay them off, although a lot of people paid for their own to be fair."
Perhaps most tellingly, two of those tickets will go to guards he got to know during his time at Thorn Cross Prison in Cheshire, where he spent the last part of his three months behind bars. "I have got them a couple of tickets," Deeney said. "I had football conversations with them, they were big on sport.
"Being up north there were Manchester United fans, Manchester City fans and Liverpool fans so me being a Birmingham fan wasn't the best - I had to talk about the Premier League all the time."
A potential windfall of £120million awaits the winner of the match. That may just be the start of an ambitious journey which manager Gianfranco Zola hopes will end with him leading the Hornets in to Europe.
"The owners want Watford to become an established team in the Premier League and with time our ambition is to be a European team," the former Chelsea striker said. "There is a long way to go. Don't forget that we are in the Championship, but that is the type of people (the Pozzos, owners of the club) are."