In 2003, Blackley was signed to the Boston Red Sox by Australia national baseball team manager Jon Deeble.
He made his debut with the GCL Red Sox that year and allowed only 13 hits in 242/3 IP, posting a remarkable 0.73 ERA.
In 2006, the southpaw was limited an injury to his elbow and spent his year back down with the GCL Red Sox (3.86) and Wilmington Blue Rocks (0–2, 4.64).
Travis pitched poorly against Mexico in 2008 for the Olympic Qualification Tournament, he left with a no-decision but Australia lost when Adam Bright struggled to relieve.
Blackley was on the provisional Australian roster for the 2009 World Baseball Classic but did not make the final cut.