While winless in four starts this campaign, Macdonald, who trains in partnership with son-in-law Andrew Gluyas, said the four-year-old was heading in the right direction.
Macdonald and Gluyas prepared Southern Speed to win the 2011 Cup in the same colours Dalasan carries on Saturday.
The trainers are buoyed by Dalasan's last start fourth behind the Chris Waller-trained trio of Verry Elleegant, Finche and Toffee Tongue in the Group 1 Turnbull Stakes (2000m) at Flemington on October 3 and the weight relief he gets from that run.
Dalasan drops from 56.5kg to 52.5kg and will be ridden by in-form Willie Pike who scored a four-timer at last week's Caulfield Guineas meeting.
"He's worked very strongly this week, looks well. I don't have an excuse for him," Macdonald told RSN927.
Dalasan will jump from barrier 10, if the three remaining emergencies don't gain a start, and Macdoanld said the entire should be able to make use of the barrier to be in a forward position.
And after doubting whether Dalasan would run a strong 2400m, Macdonald has no concerns after the entire finished second in the Group 1 South Australian Derby (2500m) at Morphettville in May.
"I think a lot will be left up to Willie Pike as to how he's ridden," Macdonald said.
"He'll do his homework and his speed-map and we'll have a bit of a talk, but I think if you can race up there in a nice position in the Cup it gives them a good chance.
"I think he'll run the 2400 metres as he's a bit older now.
"In the Derby we had our doubts a little bit, but he was beaten by a pretty fair horse and he did beat a Victoria Derby winner home."
And the rain, with between 10 and 25 mils predicted on Saturday morning, does not concern Macdonald either.
"He does handle wet tracks but it will take a fair amount of rain to make the Caulfield track soft," Macdonald said.
"It drains very well and I don't think it will be a really rain-affected track."
Dalasan has been supported at longer odds, firming from $21 to $14 with TAB since Wednesday's barrier draw.