Robbie Griffiths hopes to learn a little more about Single Note when she lines up in a mile race for mares race at Sandown.

It will be the four-year-old's second try at 1600m, her first this campaign, when she runs in the Mitavite Challenge Heat 6 on Wednesday.

Single Note finished fifth at her only previous attempt at 1600m over Sandown's Hillside course on a soft track last August.

She is off a last-start success over 1400m at Pakenham and Griffiths would have preferred another shot at 1400m, but there were no suitable options.

"I couldn't find a similar race around in mares' grade over that 1400 metre distance so we decided to extend her to 1600 metres," Griffiths said.

"She's bred to run it on the female side so we thought we'd have a crack at this and get a look at the extra distance while she's in form, coming off a win.

"This way, hopefully, it will open up some avenues to running over a longer journey."

Single Note has drawn widest of the seven runners left in the race following the scratching of topweight Vandancer.

Griffiths says Single Note races best when able to take a sit, but drawing the outside gate will make it tricky.

"She's a mare that's best with a little smother," Griffiths said.

"Last start she box-seated and everything went well and it was quite a strong win.

"Ryan Maloney will have to probably go across the field and put the brakes on to get the box seat.

"It means it may get a bit technical for us to ascertain whether she will run further."

Single Note is rated a $9 chance with the Robert Smerdon-trained Typhoon Monaco the $2 market leader.

Griffiths said the small field made it tricky, especially with a number of fit and in-form horses.

"She's fit, she's in form and she's worked well since her last start," Griffiths said.

"It's an open race. She's in there with a chance so we'll see what happens."