Trainer John MacMillan is confident Boristar is up to winning races in Melbourne - but whether that is first-up over a distance short of his best remains to be seen.

A Listed winner in Adelaide, Boristar resumes in Saturday's Sporting Globe Best Bar & Grill Handicap (1200m) at Moonee Valley.

MacMillan said he would have kicked off Boristar's campaign in Adelaide if there had been a suitable race over the same distance.

"He won his maiden over 1200 metres but he's probably better over a little bit further," MacMillan said.

"I had to start him somewhere and to wait for a 1200-metre handicap in Adelaide I would have had to wait another month."

MacMillan is looking forward to Boristar getting to his pet distance of 1400m but still rates him an each-way chance on Saturday.

"If he was to win on Saturday I would go to Caulfield in a fortnight for a 1400-metre race and be confident," MacMillan said.

"If he runs top three and is not beaten too far, I'd probably do the same."

The other option is a 1400-metre race in Adelaide.

MacMillan has prepared two Moonee Valley winners at Friday night summer meetings but the closest the trainer has been to a Saturday-grade win in Melbourne was when Boristar was beaten in a photo finish by Eclair Big Bang during last year's Melbourne Cup carnival.

After winning the Listed Christmas Handicap (1400m) at Morphettville on Boxing Day, Boristar returned to Melbourne for the Chester Manifold Stakes but the trainer said the horse choked down.

Boristar is a $9 chance in an open market with Solsay the $4.60 favourite.

"He may lack a bit of the dash of the genuine 1200-metre horses but that being said there doesn't look a huge amount of depth in that race," MacMillan said.