A native of Key West, Florida, Gabarra attended Connecticut College where he played soccer from 1978 to 1981.
After finishing college in the spring of 1982, Gabarra was signed by the Detroit Express of the American Soccer League (ASL).
The Express won the ASL championship that season, defeating the Oklahoma City Slickers two games to one to take the title.
In 1984, the United Soccer League (USL) attempted to replace the ASL as the de facto U.S. second division.
In 1984, the Louisville Thunder of the newly established American Indoor Soccer Association (AISA) signed Gabarra.
That year he led the Thunder in scoring as the team went to the AISA championship series, only to lose to the Canton Invaders.
On September 18, 1985, during the AISA off season, Gabarra signed with the Dallas Sidekicks of Major Indoor Soccer League (MISL) as a free agent.
The Heat continued its excellent play in 1990, making it to the Western Conference championship series, where it fell again to the Blackhawks.
On August 11, 2000, the Washington Freedom of the Women's United Soccer Association announced it had hired Gabarra as its first head coach.
That year the Freedom stumbled badly, finishing second to the bottom in the standings and placing no players on the All Star team.
After losing the first-round playoff game (as happened in 2009 as well), Gabarra resigned, citing "irreconcilable differences" with team management.
He left in October 2015 to become the general manager and head coach of the Washington Spirit[9] In his first year in those roles with the Spirit, the team hosted a home playoff match, won a playoff game, and advanced to the NWSL Championship for the first times in club history.
[10] The Spirit drew the Western New York Flash in regulation and extra periods before losing 4–3 in penalty kicks.