Dunne suffered a fractured clavicle during Aston Villa's Barclays Premier League defeat to Manchester City yesterday, the FAI announced today.
He did not play for the senior side though, and in February 2010 Duffy confirmed he was switching allegiances to the Republic of Ireland.
In May 2010 Duffy was rushed to hospital in Dublin after suffering a horrific injury during a Republic training game, rupturing his hepatic artery, but after undergoing life-saving surgery he was able to return to action later in the same year.
Trapatonni will be waiting anxiously on news from Birmingham this morning after Duinne underwent scans last night on a suspected dislocated shoulder.
Villa manager Alex McLeish last night predicted that the Tallaght native would be out for at least a month, depending on the extent of the hefty knock. "Dunnie's not going to be back for the next game, that's for sure," he said.
"I'm not sure what is going to happen with the big 'un, whether he is going to go to hospital tonight or whatever, or what they do if a shoulder is dislocated, whether they stick it back in. I don't know at this moment exactly what's happened.
"He's definitely damaged his shoulder which is part of the bad luck we've been having recently.
"I can't give you an answer just now, but I do believe he is going to be out for at least a month, so that's serious enough. It's not good. We won't know exactly what until tomorrow."
The 32-year-old, the rock in Ireland's defence, seems certain to be ruled out of the friendly against the Czech Republic at the end of the month, but the full extent of the injury won't be known until this morning.
With just 115 days to go until Ireland kick off their Euro 2012 campaign against Croatia, Trapattoni will be praying that the team's defensive talisman has not done serious damage.
Paul McShane could be in line for a call-up as a replacement for the February 29 clash with the Czechs -- he was left out of the initial squad.
Dunne's regular partner Sean St Ledger continued his recent run in the Leicester City team in their 2-1 win over Cardiff City, but the imminent return of fan favourite Sol Bamba -- who has been on Africa Cup of Nations duty with the Ivory Coast -- this week, could see the Ireland defender return to the sidelines.
Darren O'Dea played a full part in Leeds' 2-1 defeat to Brighton.
Another Irish international in the wars is Ciaran Clark, who faces a spell on the sidelines after tweaking knee ligaments while training on Saturday.
The Villa youngster was not named in Trapattoni's squad for the Czech friendly, but McLeish lamented his absence. "In training yesterday Ciaran caught his studs in the turf and he's tweaked his ligament," he said. "It's a real shame because we had definite plans for him tonight.
"We will lose him for a few weeks. It's not an overnight return either. It's knee ligament issues."
James McClean responded to being left out of Trapattoni's squad for the Czech test by scoring Sunderland's opening goal against Arsenal.
Although the Gunners came back, it was another impressive display from the Derry native, whose stock continues to rise.
Darron Gibson played his part in Everton's fine 2-0 win over Chelsea on Saturday before being taken off in the closing stages, while Damien Duff was celebrating success over three of his Ireland team-mates as Fulham beat a Stoke City side that featured Glenn Whelan, Jonathan Walters and Marc Wilson.