Flemington specialist Gytrash faces his most serious test on the straight course when he tackles the Group One Lightning Stakes.

The South Australian visitor is among 13 nominations taken on Monday for Saturday's dash over 1000m.

Six of the 13 entries have been prepared, or raced, interstate in the lead-up to Saturday's race which has triple Group One winner Nature Strip as the $1.60 favourite.

Star three-year-old fillies Libertini, also a nomination in the Light Fingers Stakes at Randwick, and Loving Gaby, hold down second favouritism at $6.50 with dual winner of The Everest, Redzel, next at $8 and Gytrash $10.

Richards says Gytrash has undergone a steady build-up for his autumn return after being spelled after one spring run with a knee issue.

Gytrash pulled up with bone bruising after running second to Crystal Dreamer in The Heath at Caulfield in August and while veterinary opinion was the sprinter could return later in the carnival, Richards opted to give him a good break.

"They said give him a couple of weeks off but we gave him nearly three months off and it's done him the world of good," Richards said.

"He had a gallop between races at Morphettville on the first (Feb)) with Bold Star. They only went up a half-mile and it was on a heavy track, but they ran good time.

"It was ideal for him and he pulled up really well after it, so we'll be there on Saturday and he's fighting fit."

Gytrash won at his first Flemington attempt last June over 1000m before returning later that month to win over 1200m.

Richards respects the depth of Saturday's race and says his sprinter will be strong at the finish.

"Hopefully he doesn't bomb the start and can stay in touch with them," Richards said.

After Saturday Richards plans to bring Gytrash back for the Newmarket Handicap (1200m) at Flemington on March 7 and then return home to prepare him for The Goodwood at Morphettville in May.

Mark Zahra rides Gytrash for the first time on Saturday with Craig Williams, who was aboard the sprinter at his past two starts, sticking with Loving Gaby in her return.