The Cox Plate (2040m) is also in the mix with much depending on her performance in the Maybe Diva (1600m) at Flemington on September 8.
"That's the race which will tell us which way to go," Gluyas said.
Southern Speed came within a nose of winning the Australian Cup (2000m) at weight-for-age in the autumn, when edged out by Manighar. She was spelled after twice finishing fifth in Sydney - in the Ranvet Stakes (2000m) and BMW (2400m), both won by Manighar.
TAB Sportsbet has Southern Speed at $26 for the Caulfield Cup on October 20 and $21 for the Cox Plate a week later.
The likely presence of glamour filly Samaready and the possible appearance of All Too Hard at Caulfield on Saturday emphasises the undoubted quality of the country's new crop of 3-year-olds.
But the line-up around them in the Vain Stakes for the males, and the fillies feature, the Quezette Stakes, also speaks volumes for the depth in their ranks.
Samaready makes her three-year-old debut in the listed Quezette (1100m), a race that has attracted a worthy field of challengers to Victoria's top juvenile of last season.
The opposition to Samaready is headed by the unbeaten filly Elite Elle and includes the Peter Moody-trained trio Convene, Ephemera and Mareeza, Mama's Choice from the David Hayes stable and Members Joy, trained by Robert Smerdon. But all of them would need to display something they so far haven't to be rated alongside Samaready.
The best pointer to the chances of Samaready is the internal effect she has had on trainer Mick Price.
"My gut feeling is good, I'm thinking she can win," Price said.
"She's had a good preparation, a couple of jump-outs, but not hard ones.
"She worked nicely here today on the course proper and was really happy and strong. If she's going to run in the races we've got planned for her she should be up to this," Price said.
"If she feels the pinch on Saturday, I won't be surprised.
"But horses like her usually find enough to win these races."
Samaready is destined for the Golden Rose (1400m) at Rosehill, a race that could help ease the pain of her defeat in last autumn's Golden Slipper.
The Melbourne filly started favourite and ran well coming from beyond midfield to finish third to Pierro.
Before that, she had asserted herself as the top juvenile filly in the country with her win in the Reisling Stakes at Rosehill, and Price is confident she can do the same as a three-year-old in the Golden Rose.
"I think 1400m is well within her reach, especially at Rosehill," he said.
"And you can't say no to a one-million dollar race."
In the Vain Stakes, All Too Hard, who is also entered for two races in Sydney, would meet Blue Diamond Prelude winner The Travelling Man and General Rippa, as well as stakes winners Underestimation, Cheyenne Warrior and Liberty Rock.
The depth in the 3-year-old ranks is also borne out by their absence from the nominations for the richest race of the season so far, the A$220,000 group two P B Lawrence Stakes (1400m).
Formerly the Liston Stakes, the race attracted only 13 entries with nominations extended.
Among the original nominees is Cox Plate placegetter Rekindled Interest and the West Australian Luckygray.
Trainer Jim Conlan said Rekindled Interest had come through a searching gallop at Moonee Valley last Saturday week and was likely to run.
"I'm pleased enough with the way he galloped, he picked up when he was asked and got to the line well," Conlan said.
- AAP
