"The benefit of going out early was we were able to have her ready for the early part of the spring as we are hoping to get her to a Sir Rupert Clarke or a Toorak Handicap.
"She needs to win a race or two between now and those races to get her rating up to that sort of level and this looks a good starting point on Saturday."
O'Brien also had Sass Appeal entered for the Group 3 Aurie's Star Handicap (1200m) on Saturday's card but reasoned the 1400m was a better trip.
Sass Appeal also has 1kg less (53kg) in Saturday's race as against the weight she would have been asked to carry in the shorter contest.
"She already has a good record at the 1400 (metres)," O'Brien said.
"She's won twice at the course and distance, so we thought we would stick with what she does best and is already proven at.
"It's a lower rating race than what the Aurie's Star is, a Group 3, and she is a lot better handicapped in this."