The 32-year-old former stand-off, who joined the Tigers from Worcester Warriors in 2007, has been a part of the Welford Road coaching set-up since 2010 after he was forced into premature retirement because of a foot injury.
However, Blaze has now departed his role, with development coach Brett Deacon filling the void until the Tigers find a long-term replacement.
O'Connor told the club website: "He has been an integral part of the environment for a long time. He is a student of the game and has a real attention to detail. We're sorry to lose him."
Blaze added: "I have had an amazing 10 years with the Tigers but for personal reasons I am now standing down as a coach here. I retired early as a player but I've spent seven seasons as a coach and learned such a lot.
"I would like to thank all the players, the staff and the supporters at the club and I wish the boys all the best for the future."