Fromberg was standing by the boys tournament at the Australian Open in 1987, both in single as well as double in the final. The following year, he became a professional tennis player and 1990 could win his first tournaments on the ATP World Tour. He won this year in Båstad and Bologna and reached the final of ATP Singapore. He also won at the side of Brad Pearce at the tournament in Schenectady. 1990 so was his most successful year in which he reached his highest listing in the tennis world rankings with position 24. In 1997 he won his last ATP singles tournament with the Romanian Open, the same year he won with Wayne Arthurs in Kitzbühel his second doubles title. His high for the double world rankings place he had in 1998 with 159 His best individual result at a Grand Slam tournament was reaching the second round of the Australian Open in 1993 and 1998.
Fromberg played between 1990 and 2001 14 individual lots for the Australian Davis Cup team, but also with a match in doubles with Todd Woodbridge in 1996. His record was ten wins with two losses. He stood twice in the final of the Davis Cup. In the 3-2 loss to the United States, he won his singles match against Michael Chang and Andre Agassi defeated. In the 4-1 final defeat by Germany, he defeated Marc -Kevin Goellner and defeated Michael Stich.
At the 1992 Summer Olympics in Barcelona, he went to Australia, but retired in the first round in five sets against Michael Stich from.