Durable gelding Isorich races in Listed company for the first time in Sydney when he makes the 72nd start of his career, yet the Starlight Stakes is not exactly a long-awaited goal.

Although Wyong trainer Wayne Seelin is confident his workhorse is capable of making the belated step up at Rosehill on Saturday, the 1100-metre race has been scheduled out of necessity.

Isorich's three wins in this 10-race campaign has affected the seven-year-old's benchmark, so black-type races offer the only viable weights.

"I didn't intend to run him in Listed company until he got up in the benchmarks," Seelin said.

"You can't run him in a benchmark 80 because he'll get 65 kilos and there's no 95 benchmarks on at the minute."

Seelin, who watched Isorich win back-to-back at Randwick in September, thought he would be competitive providing a good 4 was not adversely affected by forecast rain.

He also said a step back in trip and a more astute ride would be useful.

Isorich made his Listed debut last start in the Ladies Day Cup (1400m) at Hawkesbury on a five-day back-up for only the second time in his career.

He also hadn't raced over the trip since 2014, but Seelin felt apprentice Lee Magorrian's ride was the contributing factor to an eighth-placed finish.

"I wanted him to be ridden quiet so he had a chance to find the line, but he took off and sat outside the leader going hammer and tongs," Seelin said.

"That wasn't the plan."

Magorrian has been in the saddle for five of Isorich's past six races but has been replaced by Jess Taylor after being unable to make weight at 53kg.