Group One-winning mare Miss Cover Girl will need to improve in a trial this week if she is to head to Sydney for the Premiere Stakes.

Trainer Kelly Schweida had originally intended to run Miss Cover Girl in The Shorts at Randwick won by Takedown on Saturday.

However, he wasn't happy with her effort when last in a trial behind star sprinter Buffering at Doomben on September 7 and cancelled her Group Two assignment.

"She has come back a bit fat. I just wasn't happy with the way she trialled. They did go very fast in the trial but I didn't like the way she hit the line," Schweida said.

"She can trial again on Tuesday at Deagon and she will want to improve a bit on the first trial."

If Schweida is happy Miss Cover Girl will go to Sydney for the Group Two Premiere Stakes at Randwick on October 1.

"We also have the Melbourne carnival up our sleeve and there are plenty of races for her at the Magic Millions day in January," Schweida said.

Miss Cover Girl hasn't raced since she beat Azkadellia in the Tattersall's Tiara at Eagle Farm in June.

Buffering, meanwhile, worked strongly at Eagle Farm on Saturday morning. and pleased trainer Robert Heathcote.

"He threw up a bit of dirt but it was strong work. I think he is as forward as he has ever been at this stage of a preparation," Heathcote said.

"Ryan Wiggins rode Buffering and said he had never worked better."

Buffering is being aimed at a defence of the Group One Moir Stakes at Moonee Valley on September 30 with Damian Browne his jockey.