Merriman teamed up with Danielle O'Brien, who also skated at the Canterbury Olympic Ice Rink,[3] in April 1998.

O'Brien/Merriman withdrew from the 2009 Nebelhorn Trophy, the final qualifying opportunity for the 2010 Winter Olympics, due to Merriman's diagnosis of pericarditis, a viral infection in the sac surrounding the heart.

[5][2] In the 2010–11 season, O'Brien/Merriman began training part-time in Bloomfield Hills, Michigan under coaches Anjelika Krylova, two-time World champion, and Pasquale Camerlengo.

In 2012–13, O'Brien/Merriman finished 7th at the US International Classic, 4th at the 2012 Ondrej Nepela Memorial, 8th at the 2012 NRW Trophy and 4th at the 2012 Ice Challenge.

In January 2013, they became the first Australian ice dancers to medal at an International event when they took bronze at the Toruń Cup in Poland.