Harrison said the embattled Silver Ferns needed to move on and the thought of the 33-year-old defender Kopua returning to the national side did not "sit well" with her.
The Magic's Kopua, a former national captain, has been sidelined with a foot injury and last played for New Zealand in 2015. She will reportedly make herself available for the Silver Ferns if Noeline Taurua gets the coaching job.
The 35-year-old Harrison, who won four major titles with New Zealand in a career of 50-plus games, questioned if Kopua's leadership qualities would automatically work in an evolving environment.
"I just heard that [about Kopua] and actually I'm not sure about that," she told Radio Sport.
"Casey is an amazing player and if she wants to do that it's up to her.
"From a New Zealand netball point of view it's a little bit bad...you need to build players that are coming through. To bring back players, as good as Casey is, I don't know if that is the right move.
"You need to work with what you've got, can't keep going back and asking people. Casey and I are older. Coming into an environment...she might have been a great leader when she was in our team...there's [now] an age difference.
"It's a tricky one. Straight off the bat, it doesn't sit well and not something we should potentially be doing.
"No disrespect to Casey, she is an amazing player, but from a growth point of view and trying to move forward, going backward isn't the right way."
Harrison said her retirement decision was final this time after she had quit netball on a previous occasion to play beach volleyball.
"I'm known to say never say never but I'm calling time...a tough decision but I always wanted to be in control of it," she said.
"I wanted to leave when I was feeling good."
The Northern Mystics' progress was taking time to consistently appear on the court.
"I just wish you could see the flair and skill consistently — once they get that nailed everything will come together and it will be amazing to watch," she said.
