Born Bradley Christopher Harman, he signed with the Phillies organisation in 2003 and debuted with the GCL Phillies the next year. At the end of the season he led shortstops with a .928 fielding percentage. Later that year he played for the Australian under-19 national team.
In 2007, Harman hit .281 for Clearwater with 13 home runs. In the 2007 Baseball World Cup, he batted .275 and scored 11 runs in 10 games for Australia. He was one run behind the tournament leader, teammate Trent Oeltjen. Harman scored the 7th-inning go-ahead run against the Cuban national team in a game Australia lost, 3–2, in 10 innings. Harman sparked the winning rally in the bottom of the ninth inning against the Dutch national team closer Michiel van Kampen. Against Team Canada, Harman doubled in Luke Hughes with the go-ahead run in the 9th inning.
Right after the Cup ended, the Phillies added Harman to their 40-man roster. He started with the Reading Phillies in 2008 and, though he only hit .222, was called up to the majors on 20 April 2008 when Jimmy Rollins got injured. He debuted as a pinch-hitter on 22 April for Ryan Madson.
On 31 August 2009 Harman was designated for assignment by the Phillies. Four days later it was announced that he'd been selected for the Australian team at the 2009 Baseball World Cup.