The last successful Australian was Mark Woodforde in 1989, but Fromberg said he would be under no pressure as he had not even been expected to progress beyond his first-round encounter with the top seed, Marc Rosset of Switzerland.
Fromberg reached the final with a 6-4, 6-3 victory over Italy's Renzo Furlan yesterday and now meets McEnroe in a battle of unseeded players. McEnroe will also be chasing his first singles title after seven years on the tour.
"Winning a title is something I've always wanted to do," said the American, whose older brother John captured 77 singles titles.
"This is my fourth final and I've lost the previous three so it would be nice to win," said McEnroe, who earned his place by overcoming the Italian seventh seed Andrea Gaudenzi 6-3, 6-4.
In the women's event, the top four seeds - Americans Lindsay Davenport and Mary Joe Fernandez, Argentina's Gabriela Sabatini and Kimiko Date of Japan - have all reached their allotted semi-final places.
Date, the defending champion and third seed, aggravated an abdominal muscle injury in overcoming Miriam Oremans of the Netherlands 4-6, 6-2, 6-3.
Boris Becker has pulled out of the final day of the Kooyong classic in Melbourne in order to rest a knee injury, but the German says he will be fit for the Australian Open.