Blackburn was drafted by the New York Rangers in the first round of the 2001 NHL Entry Draft, 10th overall.

Born in Quebec, Blackburn moved to Canmore, Alberta as a teen and made a name for himself as a relaxed, easy-going and collected goaltender. From a young age, he attracted the attention of hockey scouts at all levels. He generally played against players two or more years older than himself and when the Bow Valley Eagles had the opportunity, they signed the local favourite. After a few Junior A seasons with the Eagles and a growing fan base, Blackburn moved on to major junior hockey with the Western Hockey League's (WHL) Kootenay Ice in Cranbrook, B.C. In 2001, he was named the Canadian Hockey League's Goaltender of the Year. While playing with the Ice, Blackburn's superb playing caught the attention of NHL scouts and he took his game from Western Canada to join the New York Rangers. In the Big Apple, Blackburn amazed hockey people by playing regularly at the young age of eighteen.

Unfortunately for Blackburn, the injury bug bit him hard and, after four seasons with the Madison Square Gardens squad, he was forced into retirement with a shoulder injury in 2005.

He retired after missing the entire 2003-04 NHL season due to a nerve injury sustained just before training camp to his left shoulder. He had nerve exploration surgery on March 31, 2004, then made an attempt to return to hockey, sporting a pair of blockers rather than the conventional blocker/catcher combination, as his injury rendered him incapable of closing his catcher. On February 1, 2005, he joined the ECHL Victoria Salmon Kings going 3-9-0, with a 3.54 GAA in 12 games. On September 15, during the Rangers training camp, he suffered a strained MCL. Subsequently, Blackburn announced his retirement on September 25. Had Blackburn continued to attempt a comeback, he would have forfeited an insurance payout of approximately 6 million dollars.