A recent Flemington double with British General and Tuscan Fire has fuelled Dan O'Sullivan's ambitions of a repeat at the same track on Saturday.

The pair won at the New Year's Day meeting and premiership leader Glen Boss has committed to both horses again but the trainer has some reservations about British General lining up in the Listed Chester Manifold Stakes.

Not because he doesn't think the horse can rise to the occasion of his first foray into black-type company, but because he doesn't want to run him in heatwave conditions.

"We want to run him and if the weather cools down then he will most likely run," O'Sullivan said.

"It doesn't seem as if it is going to be as hot as first predicted but I don't want to put him in a situation that could be stressful.

"I do think he's up to it. The field looks similar to the one he beat last time so we'll monitor the weather closely. If it's too hot he will be saved for a restricted race a week later."

The winner of six of his 10 starts, British General is one of 19 nominations for the Chester Manifold (1400m) with the Tony Vasil-trained pair Veewap (97) and Under The Eiffel (95) the top raters.

Tuscan Fire, a winner over 2000m last time out, will step up to 2500m in the Rain Lover Handicap as he continues a preparation that could encompass the Adelaide Cup and jumps features at Oakbank or Warrnambool.

An accomplished flat performer, Tuscan Fire won two of his six starts over hurdles last season.

"He showed he is the right sort of horse for jumping and we are looking at the Yalumba Hurdle at Oakbank at Easter or the Galleywood at the Warrnambool later on," O'Sullivan said.

"He's looking for the 2500 metres now and should go well on Saturday."

Among his likely opponents in the Rain Lover is his stablemate Beer Garden, runner-up to Whisper Downs at Caulfield on Saturday.