[2] In 1989, Semioli played as an amateur with the professional San Francisco Bay Blackhawks of the Western Soccer League during the collegiate off season.
Following the completion of his collegiate eligibility in the fall of 1989, Semioli signed a professional contract with the Blackhawks.
In February 1996, the Los Angeles Galaxy picked Semioli in the fifth round (44th overall) in the Inaugural MLS Draft.
[4] Semioli continues to play, and coach, in the Cosmopolitan Soccer League with the New York Athletic Club.
[citation needed]He was inducted into the Suffolk Sports Hall of Fame on Long Island in the Soccer Category with the Class of 2017.