"The biggest lesson I learnt last week was to stick to my tackles and not let someone's boot hit my jaw," he said wryly when speaking on Newstalk's 'Off The Ball' programme on Thursday night.
"Just last Tuesday in training I got a boot to the jaw. I thought it was a bit sore at the time and I went down to get an X-ray. Unfortunately I have a slight fracture.
"There was a fear that I might have to get a plate, but I've been told to stick to a strict non-chew diet so I'm on plenty of smoothies and soups and blended foods.
"Hopefully I'll avoid another operation - I'm getting another X-ray in two weeks' time and I'll hopefully be back soon after that."
It is a cruel blow for the experienced full-back who was reportedly in excellent form during the province's recent training sessions.
Duffy's 2012/13 season was hampered by hamstring injuries and he also spent some time on the wing due to the consistent performances of Athlone youngster Robbie Henshaw in the number 15 jersey.
Capped by Ireland in June, Henshaw is still in pre-season mode so he is unavailable for tomorrow's friendly away to Newcastle Falcons.
Tiernan O'Halloran and Shane Layden deputised for Duffy at full-back in the 31-7 defeat to Wasps at the Sportsground, while the returning Fionn Carr has been training in the position ahead of the trip to Newcastle.
Duffy, meanwhile, has wholeheartedly backed the new Connacht regime under Pat Lam, admiring little quirks like each player buying his own ball to improve handling skills and the fresh ideas he has brought to the table.
"It's brilliant. Obviously Eric (Elwood) was a massive influence around the place in Connacht. Whoever filled his position had big shoes to fill," admitted the Mayo man.
"Pat Lam's come in and put his own stamp on proceedings. Firstly in terms of game, it's exactly the same game we're playing but it's just a different way of playing it...just a different viewpoint.
"Little things we might have overlooked in the past or we might have focused on different areas, Pat is focusing on a completely different area of the game.
"It's very refreshing. I'm in my 12th or 13th year of professional rugby and I've learnt a hell of a lot in the last couple of months."
Allied to Lam's input, Connacht's underage and Academy structures are bearing fruit - their sub-Academy training camp had a record intake of 500 players from Under-14 to Under-20 level this summer and nine of the province's Under-20 Grand Slam-winning squad from 2011 are now on professional contracts, including senior starlets Henshaw and Kieran Marmion.
Duffy says some hugely positive steps are being taken within the province's set-up, particularly in terms of physical development and preparing young players for the rigours of the professional game.
"The young guys coming through the system, through the academies and professional academies, they are getting great work done. There's a gym in Ballina and there's one in Castlebar and the guys from 14 or 15 years of age are learning all the techniques in the gym," he added.
"It's pretty scary when they're 18 or 19 and they're coming into the gym and they're looking at you saying, 'Is that all you're lifting? Put on extra weights there!'
"They bring a whole different angle to training. Pat Lam has put it that older guys have 'credit in the bank', the younger guys are trying to catch up with that credit. They keep pushing the bar up and it's up to you then to keep pushing the bar.
"As long as those young guys keep you on your toes, you're going to respond hopefully in a positive manner and we'll see in 12 or 13 years' time if you're still at it!"