Chris Waller is on the cusp of training his 50th Group One winner, a milestone that could be reached with two strong chances in the $400,000 Makybe Diva Stakes.

Waller is sitting on 48 Group One victories but if Press Statement can win the Golden Rose in Sydney, the Flemington weight-for-age race 20 minutes later will take on added importance for Sydney's all-conquering trainer.

Appropriately, Boban is the horse considered most likely to give Waller his 50th Group One.

Boban is the most successful Group One horse racing in Waller's star-studded yard with five wins at racing's elite level.

Stable companion Weary will also line-up in the Makybe Diva but it is the last-start Memsie Stakes winner Boban which holds the call as favourite at $4.40.

It took Waller almost a decade of training in Sydney to win his first Group One race but in seven seasons since Triple Honour claimed the 2008 Doncaster Handicap, he has dominated racing.

For the past three seasons Waller has been Australia's leading Group One trainer and with 14 victories in 2014-2015 his tally was double that of his nearest rivals Gai Waterhouse and Peter Moody.

Waller admits the Makybe Diva wasn't part of Boban's spring schedule until he realised options were scarce after the six-year-old's first-up Memsie win.

"This race is an afterthought," Waller said.

"He was either going to go to the Moonga (Stakes) on Caulfield Cup day or we didn't really know what to do."

Boban won for just the second time on a rain-affected track when he rallied along the rail to beat Entirely Platinum and Stratum Star in the Memsie.

It was a three-way finish but Waller said there was enough merit in the win to give Boban his chance over 1600m, a distance at which he has won three Group One races.

"Given that he hit the line well and pulled up well he can run over the mile and then get ready for the last day of the Melbourne Cup carnival," Waller said.

Weary promises to be more than a mere stable second-stringer after running a blinder in the Memsie.

Sent forward from second last at the 800m, Weary was hunted four deep at the 600m but kept working through the line to finish fourth, 1-1/2 lengths from Boban.

Memsie scratching Fawkner will resume in the Makybe Diva as second favourite to go one better than last year when the Caulfield Cup winner was beaten in a photo by Dissident.

High-profile Cups chance Mongolian Khan also returns for his first outing since winning the ATC Australian Derby.