O'Connor, 23, missed this year's ITM Cup season because of knee construction surgery following an injury collected during the club season.
If his yo-yo test result at Blues training yesterday is an indication, his score was in the mid-17s, O'Connor is well on the way to a full recovery.
"Everything is going well ... I'll be ready for full contact early in the new year.
A Gisborne Boys' High School product, O'Connor, was a Northern Districts age group cricket representative and billeted Magpies and All Black fullback Israel Dagg when his school's 1st XI played Lindisfarne College during his fourth form year.
Because of his Super Rugby commitments he is unlikely to have any time for cricket in the Bay. While he can play any of the three loose forward positions O'Connor pointed out he prefers the No 7 jersey.
He made 17 first class appearances for Canterbury during the 2010 and'11 seasons.
"I've done my time with Canterbury and I'm excited about the opportunities I have with the Blues and Magpies," he added.
Off the field O'Connor is three papers away from completing a Bachelor of Sports Coaching degree.
O'Connor was a 2009 New Zealand under-20s teammate of Magpies Zac Guildford and Trent Boswell-Wakefield. Former Cantabs and 2012 Magpies Kieran Coll and Nick McLennan were Canterbury Colts teammates of his.
Magpies coach Craig Philpott coached O'Connor for two years when he had the Canterbury Colts team.
He approached O'Connor when another talented Canterbury openside flanker Matt Todd missed out on the All Blacks end-of-year tour to the United Kingdom.
"Obviously if Matt had made the All Blacks Brendon's chances of becoming Canterbury's No 1 openside would have increased. The fact he can also play blindside or No 8 is another plus for us and by playing for the Magpies Brendon can be closer to his parents in Gisborne," Philpott said.
O'Connor joins All Black prop Ben Franks and former All Black halfback Alby Mathewson as the Magpies key new signings to date for next season.