Finch bowed out of ODIs after leading Australia to a 3-0 series sweep of New Zealand in Cairns on Sunday but the opener remains in charge of the T20 side.
McDonald said staff were more focused on Australia's T20 World Cup defence on home soil than deciding on Finch's successor.
"It's probably the end of the (T20) World Cup really isn't it?" he told reporters.
"We have got a little bit of time to consider what those options look like.
"We've got the (T20) World Cup in front of us so that's more pressing at this stage than filling the captaincy void."
Batsman Steve Smith and current test skipper Pat Cummins are seen as strong candidates to replace Finch.
Smith led the test and one-day sides before he was suspended from international cricket for a year and banned from leadership roles for two years after the Newlands ball-tampering scandal in 2018.
Paceman Cummins took over the test side after Tim Paine stepped down from the role in the leadup to the Ashes. He has helped steer Australia to number one in the ICC's test world rankings.
Australia's next ODI matches are against England at home from November 17th, a few days after the T20 World Cup final on November 13th.
