Bruce was sacked when the crowd turned against him after a home defeat against his former club Wigan.
Harper said: "I would think he still hurts from that sacking. Certainly given the job he did, getting them to tenth in one season.
"The next year there was a difficult half dozen games, he'd lost his star striker.
"I think if he wasn't a Newcastle fan as a kid he might not have got the sack and that is a shame. "Steve's was a good record. If you look at what has happened since it stands up even better as well."
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