"As much as I'd love to be there, they're taking some different types of riders better suited to the course," Fisher-Black told NZME.
"They've already got two strong climbers and don't see me fitting in that team.
"There will be a lot of pressure and press and my team prefers not to take young riders there.
"I will definitely enjoy watching that one - a historic moment for women's cycling."
The Nelson rider finished ninth in Italy last year and targeted a top-five finish this time.
"It's always tough racing in Italy which has big long mountains," she said.
"It was a bit scary - there were some points last week which came down to just me and some of the top names in the world on the climbs.
"I grew up looking up to Annemiek van Vleuten and now I'm in press conferences with her, or sprinting against her.
"You have to believe you belong to compete with them. It's becoming more and more natural to be with them.
"I'd already done two Giros before and they went pretty well for me. I've found my strength is to repeat races day by day, and even get better during the week.
""You have to be on to it from the beginning. It was a really good 10 days."
She says she'll now refocus on the upcoming Birmingham Commonwealth Games road race, where she looks to be a genuine medal contender.
"Commonwealth Games is the next goal for me. I have a few weeks to settle back and freshen up again and refocus ... We have a really nice opportunity with the New Zealand team there and I think it should be a really good race."