Queensland jockey Luke Rolls' ride on American Diva at Eagle Farm has come under scrutiny from stewards.

The mare was last coming to the turn in a 1000m-race on Wednesday but ran on strongly to finish fourth.

Chairman of stewards Martin Knibbs said his panel had concerns about Rolls' ride in the straight.

After taking preliminary evidence from Rolls and trainer John Smerdon stewards adjourned the inquiry until they can study the sectional times.

Stewards also questioned jockey Jim Byrne and trainer Desleigh Forster about the run of short-priced favourite Rock Garden who finished fourth in a maiden on Wednesday.

Byrne said he intended to settle the filly midfield she was was reluctant to relax, pulled hard and over-raced.

Forster said she would run Rock Garden in a barrier trail without blinkers before deciding whether to take them off on race day.