Riccarton trainer Andrew Carston will use Saturday's Gr.3 Barneswood Farm Stakes (1400m) at Ashburton as the litmus test for Miss Federer's Gr.1 gavelhouse.com New Zealand 1000 Guineas (1600m) prospects.
The daughter of Swiss Ace has impressed at her two starts this spring, including a game last-start win in the Listed Canterbury Belle Stakes (1200m).
But a question mark lingers over whether the three-year-old's stamina will extend to a mile and tomorrow's stepping-stone 1400m contest is likely to provide some insight.
"I think she will get 1400m, especially at Ashburton," Carston said.
"It is a track that is suited to front-runners. It is a speed track and I am pretty confident she will get the 1400m around there. It probably depends on what sort of pressure she gets up front and I see the Pitman team have entered Okay Pal, and he has got plenty of speed.
"I am a little unsure how much pressure is going to be in the race."
Miss Federer has drawn perfectly in barrier three and will again be ridden by Kylie Williams, who rode the filly to victory last start.
"The speed that she shows from the gate, I think she will get a position, whether that is in front or near the lead," Carston said. "She is that kind of horse, she will jump and put herself there.
"I just think she is a better horse on the speed. She won't be back. The only time I did that was at Auckland and it was a disaster."
Carston said the multiple stakes winner was as tough as old boots and will dig in for the fight in a close finish.
"The only way I think she would have been beaten last time is if she hadn't seen the other horse out-wide on the track and she sling-shotted her. Kylie said she pricked her ears a bit when she saw the other horse coming.
"She is the kind of filly that loves a dogfight and we have seen that in the past."
Iain Hyndman's Ashburton Tips
1: Always, Last Hoorah, Capadanno
2: Chief Sequoya, Metasequoia, Bridget Town
3: Al Haram, Owen Patrick, Londonderry Air
4: Xplosion, I Got A Rock, Oceans Away
5: Camino Rocoso, Savapak, Upperhand
6: Sure Is, Cmpo, Devious
7: Don Carlo. Emily Margaret, Prince Oz
8: Miss Federer, Kali, Folk Dress
9: Boundtobehonored, Bella Fascino, Final Savings
Best Bet: Chief Sequoya (R2)
– NZ Racing Desk