Trebilcock was born in
Gunnislake,
Cornwall. He played for non-league
Tavistock before joining
Plymouth Argyle in December 1962. He scored 27 times in 71 league games for the Pilgrims, leading to a £23,000 move to
Everton on 31 December 1965. He made his debut a few days later against
Aston Villa, but was injured and spent much of the rest of the season on the sidelines. In the meantime, Everton had been progressing through to the FA Cup final, where they would meet
Sheffield Wednesday. Despite having only played four reserve games since his injury, Trebilcock was included in the squad and surprisingly picked ahead of
England international centre-forward
Fred Pickering to play in the final. Wednesday took a 2–0 lead with goals from
Jim McCalliog and
David Ford, but within five minutes of Ford's goal, Trebilcock had scored twice to level the scores. A goal from
Derek Temple sealed the win for Everton. Even after the cup final, he struggled to establish himself in the Everton side and in January 1968, after three goals in only 11 league games for Everton, he moved to
Portsmouth for a fee of £40,000. He was a regular goalscorer at Portsmouth, netting 33 times in 109 league games, before a free transfer took him to
Torquay United in July 1972. He spent just one season at
Plainmoor, hitting ten goals in 24 league games, leaving in June 1973 to join
Weymouth on a free transfer. In March 1974 he emigrated to
Sydney, Australia where he played for Western Suburbs and won the NSW Rothmans Medal in 1974. Having got involved in coaching, he moved in the early 1990s up to Darwin, where a professional club had been established to compete in the Singapore national league. After less than two seasons the Darwin Cubs folded due to financial problems but he stayed in the area and took various jobs. ==Honours==