The 28-year-old, locked up for assaulting a student outside a pub, entered prison with words from his mother ringing in his ears – that it was at times like that she wished he had not been born.
But Deeney rebuilt his life and his career and two years after he was released having served three months, he was appointed Watford captain, a role he retains to this day.
“The light bulb moment for me came when the door closed and my real world had stopped,” Deeney, who lost his father just before the attack which sent him to prison, said.
“It was survival mode after that. People will go ‘right yeah survival mode’ and say that’s a bit drastic but it was that.
“All my feelings and emotions cut off as I said to myself ‘you’ve got to get through this next few months’.
“I didn’t have enough time to sulk or cry and do all the things you would think are natural reactions.
“If my mum died now I’d be a mess. I’d be crying all over the place and drinking loads of beer like everyone else would. I didn’t have that luxury.”
Deeney said incarceration transformed him for the better.
“I always knew I would come out better but it was about how I went about doing it,” said Deeney.
“Part of the course was alcohol dependency which was compulsory if I was to be eligible for a tag (to wear on early release).
‘I got into speaking, I used to be closed and have a lot of anger in me, at the group sessions.
“I still speak to a psychologist. People feel sorry for themselves and think the world owes them something and then you realise it’s not that bad.”
Deeney, now teetotal, was particularly close to the man he called his father, Paul Anthony Burke – his biological father left home early on. He has a tattoo which bears Burke’s date of birth and death.
It was to Burke that Deeney’s thoughts turned to when Watford gained automatic promotion to the Premier League in the 2014/15 season.
“I just cried,” admits Deeney. “I remember I found out on the bus that we got promoted as other results went our way – everyone went crazy.”
He added: “I always wanted to be a footballer and always liked the idea of playing in the Premier League. I had played in League One (the third tier) with Walsall, then the Championship.
“My dad and granddad would be so proud. I rang my wife (Stacey and mother of their two children, Myles and Amelia) and said I’m going there to his graveside.
‘However, at six in the evening it was shut so I went out with the team.
“Then the next morning I went with a Thermos of tea to the cemetery and had a cup of tea and sat there talking to his gravestone.”
Deeney, who has set up his own foundation to help seriously ill children and distributes football kit to youngsters on the tough estate where he once lived in Birmingham, says he has used his prison experience to advise young offenders.
“I would probably stay away from talking in prisons because I had a career going in and I had one going out,” said Deeney, who invited two of the prison guards to the Championship play-off final in 2014 as a way of thanking them for encouraging him to go to the prison gym and keep fit.
“I can’t resonate with a lot of people there as there are a lot who have lived on that same road (crime) and once they are out they go back to doing the same thing.
“Driving out there in a Range Rover probably doesn’t sit well with them,” added Deeney, who nevertheless stays in touch with two of the inmates he considers friends.