There is no knock on Numerian since he arrived in Perth, but Rob Archibald says the eight-year-old will need to be at his top to win the Group 2 Ted Van Heemst Stakes at Ascot.

Archibald believes if Numerian can run close to the level he displayed earlier this year in Brisbane and Melbourne, he has the class to win the Perth Cup lead-up race, but he's cautious.

Numerian, trained by Annabel Neasham ​​​​​​, finished runner-up to Cascadian in the Australian Cup (2000m) at Flemington, beaten three-quarters of a length after leading for the majority of the race.

Holding that form in elite company two starts following, Numerian filled the same placing when he pushed Huetor to a neck in the Doomben Cup (2000m).

But it's been slim pickings for Numerian since the Doomben second and that's the concern for Archibald, further evidenced when coming up empty-handed in the spring.

A son of Holy Roman Emperor, Numerian hasn't fired a shot in three attempts and tackles Perth for the first time after a seventh to Stroke Of Luck at Newcastle last month.

Archibald says Numerian has settled in well to his new environment but needs to rediscover his best effort to be capable of winning on debut in Perth.

"All the reports have been good and obviously a bit of time between runs, but the freshen-up we felt would do him the world of good," Archibald said.

"I think he's going to have to improve a little bit on the way he's been going, but he's a class horse.

"He has to get back to that old form where he ran second in the Australian Cup and second in the Doomben Cup.

"His best form is very much up to these, but you have to respect the locals who are seasoned performers.

"I'm certainly not taking the race lightly but hopefully he can get the job done.

"He's a class horse and on his day if right he can certainly be up to these."

The Ted Van Heemst Stakes has attracted a six-horse lineup with Numerian to come out of gate two for jockey Clint Johnston-Porter.

The Neasham stable is back in Perth hoping to go one better after stable star Zaaki ran an agonising second to Dom To Shoot in the Group 1 Northerly Stakes.

Archibald said Numerian will progress to the Perth Cup (2400m) on January 1 if he pulls up well from the Ted Van Heemst Stakes.