Melbourne debuted in the first ABL season, 1989-1990, going 24-16 and placing second to the Waverley Reds. They were managed by John Galloway. Despite their high finish, they had no first-team All-Stars and their only league leader was C Randy Knorr (.617 SLG). Knorr and SS Richard Vagg (42 R, .357) were second-team All-Stars while Anthony Ward was their top pitcher. They were expelled from the league and replaced by the Melbourne Bushrangers for the next two years.
When the Bushrangers moved to Canberra, the Monarchs returned in 1992-1993; they won their only title. Jon Deeble would manage them for the remainder of the decade. They were 28-19 in the regular season, second to the Sydney Blues, but beat Sydney for the title behind playoff MVP Don Lemon and Barry Parisotto, both import pitchers. They boasted first-team All-Stars in OF Ron Carothers and RP Ross Jones (a league-best 13 saves), while Deeble made second-team at both 1B and manager.
In 1993-1994, the Monarchs fell to 29-26 and 5th place. Jarod Juelsgaard finished second in the league with a 2.67 ERA while Jones led with 10 saves and repeated as the league's All-Star RP. Deeble's club faded to 27-36 and 6th place in 1994-1995, thanks to a 5.33 ERA. Jones led the league in saves (9) for the third straight year but fell to second-team All-Star, while Carothers returned to the first team.
Melbourne was 24-24 in 1995-1996 but remained 6th. Player-manager Deeble led the league in ERA (2.68), David Buckthorpe led in walks (28, tied) and Earl Byrne was second in strikeouts (75) but they lacked a first-team All-Star and had only one second-teamer, C Vance Wilson. In 1996-1997, the Monarchs had their third straight sixth-place finish at 28-29. They did boast the league's top two starters, though, with first-team All-Star Kevin Millwood and second-teamer Phil Dale. Millwood was third in ERA (3.44), tied for 3rd in wins (8) and led with 92 strikeouts and Dale tied for first with 9 wins and was third with 85 whiffs.
Deeble's club improved to 32-20 in 1997-1998, winning the regular season, but they fell in the round-robin playoffs, dropping contests to the Gold Coast Cougars and Sydney Storm. They again had a good pitching duo of an import hurler to join with native-born Dale. This time, Erick Nelson won Pitcher of the Year by leading in ERA (2.83) and finishing third in wins (7). Dale tied for the win lead (8) and led with 95 strikeouts. In the ABL's final year, the Melbourne Monarchs fell to 22-22 and 4th place. Paul Gonzalez led the loop with a .478 OBP and was named the first-team All-Star at 3B. Jason Flach was second in the circuit with 74 strikeouts while Mike Nakamura had a great K rate.
Source: Flintoff & Dunn Australian Baseball Almanac