John was born in Tunapuna, Trinidad and Tobago,[1] to a sporting family that included several professional footballers and cricket players.

[5] John led the Mercer County Vikings to the 1995 NJCAA soccer championship and scored 27 goals, including one in the final against Yavapai College.

[6][7] He made his professional debut for the Carolina Dynamo of the A-League, the second division of U.S. club soccer, in April 1997 while on loan from the Trinidad and Tobago Football Association.

[9][10] With New Orleans, where he was paired with fellow Trinidadian forward Mickey Trotman, John scored 16 goals in 21 appearances and was named Rookie of the Year.

[10] His second cousin Ansil Elcock, a fellow Trinidad and Tobago international who had been signed by the Crew,[13] had recommended John to head coach Tom Fitzgerald.

[3] Following a successful trial, John was signed and made his Major League Soccer debut on 29 March 1998 against the Dallas Burn, where he replaced Elcock but failed to score.

[22] Popular with the Birmingham fans for his goals,[23] he nonetheless fell out of favour with management, and was sold to Coventry City on 14 September 2004.

At the start of the 2005–06 season, following the signing of James Scowcroft, John found himself outside of manager Micky Adams's first-team plans.

On 29 August 2007, John moved to Southampton as part of a deal that took his international teammate Kenwyne Jones in the opposite direction.

From then on he scored regularly for "The Saints", with nine goals in his first fifteen appearances, including a second half hat trick against Hull City on 8 December 2007.

Before being sent off for a second bookable offence, John scored two goals, including the match winner, in Southampton's final game of the season against Sheffield United, as the Saints narrowly avoided relegation to League One.

He came out of retirement a second time in order to join WASA FC of the National Super League of Trinidad and Tobago in January 2014.

[36][37] As a member of the squad that competed at the 2006 FIFA World Cup in Germany, John was awarded the Chaconia Medal (Gold Class), the second highest state decoration of Trinidad and Tobago.