He was a member of the New Zealand side that won the 2008 World Cup, and has captained the team and played for the NRL All Stars.

[3] Blair played his junior football for the Northland Carvers and attended Whangarei Boys' High School before recruited by the Melbourne Storm as a 16-year-old where he moved to Brisbane, Queensland and played for their feeder club the Norths Devils with Greg Inglis while attending Wavell State High School.

Awarded with selection in the New Zealand national rugby league team 2006 Tri-Nations series squad,[10] Blair made his international debut against Australia, playing off the interchange bench in the 30–18 loss at Mt Smart Stadium on 14 October.

[11] Blair played in all 4 matches of the tournament including the Kiwis 16-12 Tri-Nations Final loss against Australia.

[12] Blair missed most of the 2007 NRL season due to a foot injury which he suffered in the last year's Tri-Nations Final, playing in only 8 matches for the Storm.

[14] In the Storm's preliminary finals match against the Cronulla-Sutherland Sharks, Blair scored his first NRL career try in the 28–0 win at Sydney Football Stadium.

[15][16] On 5 October, Blair played off the bench in the Storm's 40-0 Grand Final loss to the Manly-Warringah Sea Eagles.

In the match against Papua New Guinea, Blair scored his first international try and was named as the Man-of-the-Match in the 48–6 win at Cbus Super Stadium.

[20] On 4 October, Blair played in the Storm's 2009 NRL Grand Final against the Parramatta Eels, where he started at second-row and scored the second try of the match and set up Billy Slater's try to lead the team to the 23–16 victory.

[25] On 13 November, in New Zealand's Four Nations Final match against Australia, Blair started at prop as the Kiwis won 16-12 after a try to Nathan Fien with 2 minutes to fulltime.

In Round 2 against the Gold Coast Titans, Blair played his 100th NRL career match in the Storm's 40–12 win at AAMI Park.

In Round 1 of the 2012 NRL season, Blair made his club debut for the Wests Tigers against the Cronulla-Sutherland Sharks, where he started at second-row in the 17–16 win at Leichhardt Oval.

[36] In the next match in Round 2 against the Manly, Blair scored his first try for the Tigers in the 22–18 loss at Central Coast Stadium.

However, with an average of 3 missed tackles a game and low yardage achieved with the ball, Blair was described as one of, "the biggest flops of 2012."

"[48] In Round 1, Blair made his debut for the Brisbane Broncos against the South Sydney Rabbitohs, starting at prop in the 36–6 loss at Suncorp Stadium.

[62] Blair was named captain of New Zealand for the World Cup due to Jesse Bromwich being stripped of the captaincy after he and Kevin Proctor were caught in possession of cocaine after the test.

In Round 11 against one of his former clubs the Wests Tigers, Blair played his 250th NRL match in the 36–0 win at Suncorp Stadium.

[69] Blair played in all of the 4 matches at lock in the Kiwis disappointing campaign after losses to second-tier teams Tonga and Fiji.

[71] In Round 1 of the 2018 NRL season, Blair made his club debut for the New Zealand Warriors against the South Sydney Rabbitohs, starting at prop in their 32–20 win at Perth Stadium.

In the last week of 2020 National Rugby League Season Blair would announce his retirement from playing career.

In the 2021 Queen's Birthday Honours, Blair was appointed a Member of the New Zealand Order of Merit, for services to rugby league.