Thomas made his senior debut in
Burnley's 8–1 defeat to
West Bromwich Albion in the 1966–67 season. Thomas's most successful season was undoubtedly
1975–76 while playing for
Queens Park Rangers. QPR led the First Division for much of the season, narrowly missing out by one point to Liverpool after the final game of the season. Thomas was a pivotal figure in the team, providing
Stan Bowles,
Gerry Francis and others with outstanding service from the wing. Following his transfer to Everton, Thomas continued to enjoy success in the
1977–78 season while playing for Everton. Everton's top marksman
Bob Latchford scored 30 goals in the league that season, Thomas providing more of his goals than anybody else with some more accurate crosses. His transfer in October 1972 from Burnley to QPR for £165,000 was a then record fee for a Second Division club. In 1981, Thomas played a single summer season with the
Vancouver Whitecaps in the
North American Soccer League. ==International career==