Officials will wait until race morning to decide whether the midweek city twilight meeting at Caulfield and another fixture at Yarra Valley will go ahead.

A race meeting at Werribee on Tuesday was called off on race morning because of smoke haze and hazardous air quality resulting from bushfires in NSW and Victoria.

Caulfield is scheduled to host an eight-race twilight meeting on Wednesday with the first race at 3.40pm, while the eight-race Yarra Valley card has a 1pm start.

Racing Victoria said it would make the decision at 7am.

Trainer Phillip Stokes has Sansom in line to run at Caulfield in the Ladbrokes Odds Boost Handicap (1200m) but on Tuesday said there was also a back-up option at Flemington on Saturday.

Sansom won twice on the Pakenham synthetic track and once at Sandown as a late-season two-year-old before being spelled after failing in a race at Flemington in early August.

He made a winning return against his fellow three-year-olds at Mornington over 1000m on January 1 and will be tested in city grade again against older horses if he runs in Wednesday's benchmark-70 race.

Stokes believes dropping 4kg from last start to 56.5kg after apprentice Tom Stockdale's 3kg claim will be key to his chances.

"I thought his first-up win was good because he gave the second horse almost 10 kilos and did what he had to do," Stokes said.

"A couple of our horses didn't winter that great so I still feel he's got improvement to come. But he worked really well on Saturday and he goes to Caulfield where he has a big drop in weight.

"I still feel he is a preparation away, physically and mentally, but he is starting to get a little bit of a record around him now."