Australia optimistic for Travis Head to start World Cup against Netherlands
Head, who fractured his left hand during Australia's South Africa tour last month, missed his team's first four matches at the World Cup in India.
McDonald said selectors would make a call on the lefthander's availability after seeing how he recovers after training later on Monday.
"We're really optimistic that he'll be available should all things go well today and as I said, most importantly, the way he pulls up tomorrow will be a key factor," McDonald told reporters.
"It's been really impressive the way he's gone about his recovery."
Marnus Labuschagne is expected to make way should Head return for the match on Wednesday at Delhi's Arun Jaitley Stadium but McDonald said that was not clear-cut.
"We'll just wait and see what it looks like in terms of the Netherlands if Head is fit," he added.
Australia are fourth in the group stage standings, having steadied their campaign with successive wins over Sri Lanka and Pakistan following heavy defeats against hosts India and South Africa.
The top four make the semi-finals.
McDonald said Australia were targeting more powerplay wickets, having been thwarted by strong opening batting partnerships in their last three matches.
However, the team are likely to persist with seamers Mitchell Starc and Josh Hazlewood opening the bowling, rather than starting with fast-bowling captain Pat Cummins.
"Ideally we don't want to be relying on middle over wickets," said McDonald.
"That combination of Starc and Hazlewood have really dove-tailed well in the powerplay. One's economy rate is ridiculously good and the other one's got the wicket-taking ability.
"We feel like that's a really good combination."