Stewards have launched an inquiry into jockey Tim Clark's tactics on heavily backed Washington Heights at Rosehill.

Stewards expressed concern with Clark's ride in the Spring Preview on Saturday after the $2.60 favourite could not find a run in the straight and finished fourth.

Chief steward Marc van Gestel argued Clark should have positioned Washington Heights outside eventual winner Kingsguard at the top of the straight to follow eventual third placegetter Etymology.

After racing in seventh position, Washington Heights saved ground as Clark decided to stay on the inside of runners.

Along with subsequent runner-up Tom Melbourne, Washington Heights was blocked for a run and was not properly tested in finishing 1-1/2 lengths from Kingsguard.

"I've seen Tom Melbourne travel strongly and if he does get room he probably wins the race. I follow him through and it's a great decision," Clark said.

"I think I'm around the right horses. The runs just haven't eventuated for me."

Clark said if he angled his mount to where van Gestel suggested he should have, the move might have endangered his fellow riders.

When quizzed by stewards, Clark said he had only discussed the race with his manager, John Walter, via mobile telephone.

Racing NSW investigator Nathan Hayward scanned the device and confirmed there had been a brief exchange of texts.

Walter initiated the exchange, writing: "Hope they go hard in Washington's race."

Clark replied: "Washington will be in front of three or so."

Washington Heights' trainer, Gerald Ryan, who had expected the horse to win, was not critical of Clark's ride.

"I just thought he rode for luck and it probably never happened," Ryan said.