As a junior, Humphries reach the doubles finals of two
Grand Slam tournaments and finished runner up in both. At the
1993 Australian Open alongside compatriot Jimmy Jackson they lost
7–6, 5–7, 2–6 to German duo
Lars Rehmann and Christian Tambue, and the then at the
1994 US Open playing with a different compatriot
Paul Goldstein they lost to
Nicolás Lapentti and
Ben Ellwood 0–6, 2–6. Humphries won the
1994 Wimbledon Championships boys' singles title, defeating
Mark Philippoussis of Australia
7–6, 3–6, 6–4 in the championship match. ==Junior Grand Slam finals==