Hence McGrath has lauded Cummins' move to skip the IPL, warning proper rest must be built into their schedules.
The combination of Cummins, Hazlewood and Starc in Twenty20 cricket has come under the microscope following Australia's early World Cup exit.
Questions have been raised whether the pace bowling trio should be kept for all formats or selectors look to the future with the 2024 World Cup in mind.
But Australia's greatest fast bowler is unmoved.
"The bowlers have adapted," McGrath told AAP.
"Josh Hazlewood is one of the world's best T20 bowlers. He has shown that in the past with the way he has gone about it.
"Pat Cummins can adapt just because of the areas he bowls.
"Starcy's a match winner when he gets it right. He is as good as anyone in the world.
"I have no issues there with our bowling attack."
What McGrath is concerned about is the amount of cricket required for the trio to play all formats.
Australia's series opener against West Indies in Perth from Wednesday is the first of up to 15 Tests in the next nine months, while a one-day World Cup also looms next October.
McGrath is not a believer in resting bowlers for individual matches, saying it has more impact on a player's mindset than resting the body.
"Resting bowlers throughout a season from a game here to a game there, that was my biggest risk of getting injured," McGrath said.
"That's a band-aid solution. I want our players and especially our bowlers working at 95 per cent or more."
Instead he believes bowlers must be given proper long breaks.
All three of Australia's front-line quicks will skip this summer's BBL, a position they could be under pressure to change from as soon as next summer.
Cummins this month also joined Starc in deciding to skip the lucrative IPL over concerns about workload, while Hazlewood is still considering his options.
"You don't want to de-value the Big Bash, but you have to weigh up what is important," McGrath said.
"Playing for Australia should still be the be-all and end-all. Test cricket is still the ultimate.
"Fast bowlers need to have a bit of an off-season because bowling and running depletes your strength. And you need that strength so you don't have injuries.
"The fact they may not be getting that as much now is an issue.
"Cummo has come out and said he's not going to the next IPL. That's where you have your off-season, get strong and get through the next season.
"If you don't do that you're a car that never re-fuels. Sooner or later you're going to run out."
9°C