Bow Creek is a firming favourite for the Australian Cup with uncertainty about second favourite Palentino lining up.

Last Saturday's Australian Guineas winner came in for support when trainer Darren Weir announced he was considering backing the three-year-old up against the older horses.

But the Alister Clark Stakes at Moonee Valley on March 18 has emerged as the favoured option for Palentino.

Bow Creek, to be ridden by Damien Oliver, is now at $3.10 for Saturday's Australian Cup (2000m) at Flemington.

With Palentino a doubtful starter, there may only be 11 runners in the $1.5 million race.

A field of 10, headlined by Chautauqua, is expected to line up in the feature sprint, the Newmarket Handicap.

Chautauqua is the $2.40 favourite to break his duck in Group One races on the 1200m straight course having finished runner-up in last year's Newmarket and in two Darley Classics.