The two official 2017 Golden Slipper Stakes lead-up races run in Sydney on Saturday, but Canberra on Sunday could reveal a genuine contender for the $3.5 million classic with the running of the Black Opal Stakes.

Magic Millions Classic winner Houtzen may bypass Sydney on Saturday in favour of a 2017 Black Opal Stakes run in Canberra on Sunday. Photo: Steve Hart.

Two ballot exemptions are on offer in the opening two races at Royal Randwick this weekend with the running of the $300,000 Group 2 Reisling Stakes (1200m) for the fillies and the $300,000 Group 2 Todman Stakes (1200m) for colts and geldings.

A Heavy-rated track and persistent rainfall in Sydney however threatens the postponement of the Randwick Guineas Day card.

Should the dual Group 1 meeting go ahead, the mud course could scare away plenty of the two-year-olds engaged in the opening two races according to Canberra Racing chief executive Peter Stubbs.

“If they’re not in [Canberra] on Sunday, they’ve got to run in Sydney on Saturday,” Stubbs said.

“Randwick will be rain-affected, so there’ll be a bit to work out before the final [Black Opal] field is settled.”

A host of juveniles accepted in the Reisling and Todman Stakes fields are also nominated for a run at Thoroughbred Park in the ATC the following day in the $300,000 Group 3 Black Opal Stakes (1200m) including Houtzen.

The undefeated Toby Edmonds-trained I Am Invincible filly is the $8 second favourite behind She Will Reign in futures Golden Slipper Stakes betting at Ladbrokes.com.au.

Last seen winning the $2 million Gold Coast Magic Millions 2YO Classic (1200m) at her home track in mid-January, Edmonds is yet to make a final call on the Reisling Stakes or Black Opal Stakes for the filly’s next run.

“I’m just going to leave my options open,” Edmonds told the Canberra Times.

“If we can get [to Canberra], we’d love to run her there but it’ll just depend. She’ll run well wherever she goes.

“She’s a pretty sharp filly, so I’d imagine she’d be one of the top chances in the race, depending on barrier draws and stuff.”

Among the Todman Stakes accepted colts and geldings that could end up in Canberra instead include the Gerald Ryan-trained Chauffeur and Menari, Ciaron Maher’s Ladbrokes Blue Diamond Stakes scratching Jukebox and Khan.

Peter & Paul Snowden had what looked like a key Golden Slipper Stakes contender early in the picture when Exceed And Excel colt Khan won the Listed Breeders Plate (1000m) at Randwick last October on debut.

He returned to racing in the Group 2 Silver Slipper Stakes (1100m) at Rosehill on February 18 and only managed to run over six lengths back seventh when dead last behind She Will Reign.

Khan has eased right out to a $41 roughie in pre-field Golden Slipper Stakes odds to hand the stable successive wins in the classic after the success of Capitalist (2016) last Sydney Autumn Racing Carnival.

Co-trainer Peter Snowden, who also prepared Sepoy for his Golden Slipper success in 2011, believes Khan has the ability to bounce back into contention for the Group 1.

The official 2017 Black Opal Stakes field is set for release on Thursday, while Golden Slipper betting is open right now at Ladbrokes.com.au.