Golden Slipper winner She Will Reign is likely to miss the $2.5 million Group One TJ Smith Stakes to avoid a clash with benchmark sprinter Redzel.
"I think she's not quite there myself, not mature enough to take on the big guns at the moment," Portelli said after watching She Will Reign gallop between races at Warwick Farm on Wednesday.
"Redzel and company at 1200 metres around that big track at Randwick, I know we get a bit of weight relief, but this year we don't get as much," he said.
With Kerrin McEvoy riding, She Will Reign worked with a stablemate over 800m at Warwick Farm as part of her build-up to the Group One William Reid Stakes at Moonee Valley on Friday week.
The three-year-old ran her last 600m in 34.33 seconds.
She Will Reign will return to the scene of her Group One Moir Stakes triumph when she contests the William Reid.
"I think that'll give us a better look at her and give us a choice on whether we want to take the lower road at this point and worry about TJ next year."
She Will Reign is also nominated for the Arrowfield Sprint over 1200m on the second day of The Championships at Randwick.