Franklin was one of Australia's best players in the Indigenous All-Stars' 22-point loss to Ireland at Breffni Park in Cavan, but is set to board a return flight for Australia on Sunday morning.
The Sydney Swans' recent prized signing told AFL.com.au on Saturday night he would leave Ireland with mixed feelings.
"I would love to stay here but I've got to get back for one of my best mate's, Brent Guerra's, wedding," Franklin said.
"It's going to be hard leaving all the boys behind and I'd love to be out there for that Second Test, but unfortunately I won't be able to get there."
The future of the International Rules Series has been questioned by some sections of the media, but Franklin said the chance to represent Australia as part of an all-indigenous team had been "unbelievable".
"I've tried to get this up and running for a long time and to see the boys out there today was exceptional and to represent indigenous people and Australia means the world not only to me but all the boys in there tonight," Franklin said.
"So hopefully this concept can keep running and we can get the victory next week and from there we can keep it going."
Franklin played a crucial role for the Australians at Breffni Park with his work in attack and as a ruckman at centre bounces.
"It was a little bit different," Franklin said of his turns in the ruck.
"I haven't played in the ruck since I was a little fella, so I hope John Longmire doesn't have any plans there."
Perhaps the turning point of Saturday night's game came at the five-minute mark of the final quarter.
Having come from 25 points behind late in the third quarter, the Aussies were suddenly within 11 points when Steven Motlop took a handball from Eddie Betts that set him up to goal from point-blank range.
Almost unbelievably, Motlop kicked the ball into the crossbar, Ireland dodged a bullet and went on to steady and run out comfortable winners.
Mathew Stokes later told AFL.com.au his Geelong teammate's uncharacteristic error could not be blamed for Australia's loss.
"We were really back in the game at that stage but you don't want to say that because of somebody's skill error that we could have got back in the game," Stokes said.
"I thought they were obviously better than us tonight and they've been in camp for six or seven weeks, but full credit to them, they outplayed us tonight."
Stokes said it had been a very proud moment when the Australian team performed the war cry before the first Test.
"I didn't know how I was going to feel about it before the game," Stokes said.
"I was really nervous and wanted to do it properly, but once we got out there and the boys started standing around waiting to do it the emotion took over and it was such a proud moment for us boys and hopefully the people back home."