The magnitude of the decision isn't lost on the 30-year-old given women's cycling is crying for exposure, and the Games will garner more domestic publicity than European feats.
Spratt (Mitchelton-Scott) wavered a couple of times before making the now resolute call ahead of Sunday's national road titles, which will mark the start of her 2018 season.
"It was a decision I made with my coaches and the team to focus on the Ardennes instead in that period," she said.
"Emotionally I really want to do the Commonwealth Games but practically I want to get better at those big one-day races and the Ardennes are the ones that suit me the most."
Spratt said she "absolutely hated the idea" when it was first posed to her in August.
"I thought, no way, there's no way I would sacrifice that. We spoke about it again in October and I still had the same feelings," she said.
"Then I sat down and thought about it … and I really want to become one of the best in the world.
"I'm at a point in my career where I have to prioritise and the best way forward in terms of improving myself is to really focus on those [Ardennes] races.
"People won't expect it as a female racer because I know the Comm Games are a really great opportunity to get a big result. It's not taking anything away from getting a result there, but it's more what can … move me forward in my career as well."
Spratt is playing the long-game looking toward not just the European season, but the world titles in Austria later this year as well as the Tokyo 2020 Olympic Games.
The two-time national champion didn't have a remarkable Ardennes campaign last year, although notably bounced back marking a stint in the leader's jersey and finishing fifth overall at the Emakumeen Bira tour, fifth overall at the Giro d'Italia and fifth at La course (Marseille).
That came off the back of a successful early season run on home turf where Spratt finished second to former teammate Katrin Garfoot at the national championships and claimed overall victory at the Santos Women's Tour.
She aims to go one better in Ballarat this weekend with Mitchelton-Scott, which, on paper, has the strongest line-up.
"We'll use everything we have to get that jersey," she said.