Cummins endured his most difficult moment since taking over the leadership role in October as England pressed for a series-levelling victory only to be foiled by inclement weather as Australia retained the Ashes urn.
Cummins, both as Australia's leader and pace spearhead, looked helpless against the swashbuckling batting of Zak Crawley and Jonny Bairstow, while the short-pitched bowling ploy he employed came a cropper against England's aggressive 'Bazball' approach.
Former Victoria captain Darren Berry (53) criticised Australia's approach and predicted Cummins, who bled 5.6 runs an over in the match, would step down after the final test at The Oval beginning on Thursday.
McDonald termed Berry's comments "most interesting".
"What I would say is leadership takes on all different shapes and forms and we're living and dying in the world of tactics only," the coach told reporters.
"I think it's fair and reasonable to critique some of the execution and tactics that we implemented but to go as far as suggesting that the captain resigns post-series, I think it would be far-fetched.
"There's opinions that we respect and there's opinions that we don't."
Asked if he thought Cummins had become a soft target, McDonald said, "We're all working on the Australian cricket team together. It should never really come down to Pat as an individual but unfortunately, as a captain, sometimes you wear that."
Cummins, who has played all four matches of the series, has denied the burden of captaincy affected his own performance with the ball.
"I don't think (that was an issue)," Cummins said after the draw.
"It was just execution, I let through more boundaries than I normally do. Probably just one or two bad balls an over."
One thing he was sure about was that Australia, who did not play a specialist spinner at Old Trafford, would have to review their strategy heading into the final test.
"You definitely look at what you can try and do differently for next time. That will be part of this week for sure," Cummins said.
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