The Irish will host Australia in their first 50-over meeting since the 2007 World Cup, when they were soundly beaten by nine wickets.
Ireland have managed just two wins in 17 ODIs against Test-playing nations in their short history, the most notable of which came against Pakistan at the Caribbean World Cup three years ago.
And while Porterfield is hopeful rather than expectant of beating that high watermark success, he believes it is not beyond his side.
“It doesn’t get any bigger, taking someone down in your own backyard, the world champions,” he said.
“We’ve been looking forward to that since the fixture came out.
“Everyone in the squad has yapped about it at some time. Beating them, or scoring the winning runs or taking the winning wicket, making that match-winning performance.”
“We have to step up tomorrow and put it all together and perform. If we do that, then we’ve got a great chance of doing something special.”
Coach Phil Simmons echoed Porterfield’s positivity: “You always believe. It’s a two-horse race, there’s a 50% chance you can always win.
“I keep saying this to all the top countries. Once we play to the best of our ability and they take us lightly or (we) step up on the day, we have a chance of beating them.
“Every time we go out there, that’s what we want to do. Play to the best of our ability and look for that little slip-up on the day.
“One-day cricket and Twenty20, one slip-up and you’re dead.”
The Irish were dealt a blow yesterday with all-rounder Andre Botha ruled out of the match with injury.
Regardless, the positive mood inside the Irish camp was evident as they enjoyed a spirited training session at Clontarf, which finished with a 45-minute coaching session with Australia’s fielding coach, Mike Young.
Simmons made the unconventional request for Young to speak to his players after being disappointed with their fielding in last month’s ICC World Twenty20 and thanked the Australians for allowing his players to gain an insight from the American former minor league baseballer.
“It’s just a case that after the T20 World Cup, one of the things we need to get a lot better is our throwing, hitting the stumps and throwing from the boundary,” he said.
“I didn’t think we were at the same standard as some of the other teams, namely Australia, South Africa and West Indies.
He added: “The one thing that you know about Australian cricket, is they share their knowledge.
“Even though they are the best team in the world, they don’t keep everything to themselves. They do share things.
“I don’t think they give everything away but they share and try to help the smaller countries like us.”
Young’s coaching session may have been insightful for more reason than just fielding after Porterfield, one of Ireland’s best fielders, revealed he had warned his side not to expect any favour from an Australian side looking to kick-off their two-month tour of Ireland and England with a win.
“That’s what Mike Young said, the one thing they won’t be doing is they won’t be taking us lightly,” Porterfield said.
“If anything was going to reinforce that to the lads, that was it.”