Hazlewood is one of several big names sitting out Australia's Twenty20 World Cup campaign due to injury, as the side prepare to face co-hosts Sri Lanka on Friday.
The 35-year-old has not played since November, missing Australia's 4-1 Ashes series triumph when first struck down by a hamstring strain before an achilles injury.
Australia's next red-ball series is against Bangladesh in August, beginning the busiest 12 months in the team's history with up to 21 Tests in the space of a year.
An ODI World Cup follows in South Africa next September, with Hazlewood still Australia's top-ranked bowler in the 50-over format.
The busy run comes at a time when the team's age remains a constant talking point, with Pat Cummins the youngest regular bowler at 32.
Man-of-the-series Starc routinely pointed to that experience as crucial in the Ashes, with he, Pat Cummins and Nathan Lyon largely injury free before this summer.
Hazlewood, though, has faced the most questions about his future of anyone.
This summer was the second straight ruined by injury, after calf and side strain issues limited him to two Tests against India in 2024-25.
The seamer has taken 57 wickets at 15.82 to be Australia's best when on the field in the past two-and-a-half years, after a difficult run with injuries between 2021 and 2023.
But Starc said questions over Hazlewood's future would not faze his long-time teammate, who does not use social media.
"He doesn't pay any attention to it. He'll be frustrated and disappointed anyway because he wants to play Test cricket," Starc told AAP an Amazon Prime Video event.
"He's had a couple now where he's been flying into summer and missed out a fair bit.
"When you get to our age, people start questioning that sort of thing (about your future).
"I know and see how hard he trains, how good he is with rehab. He's pretty rigid in how he wants to approach things.
"Once he gets past this frustrating setback ... there's a lot of cricket to play in the next two years. And he's going to be a big part of that."
Making Hazlewood's injury more frustrating is the fact he was Australia's form bowler ahead of the Ashes, starring in white-ball matches against India.
Starc trained with him this week, and is certain the veteran still had a desire to make an impactful return.
"Considering the bum run he's had for the whole summer, he's in good spirits," Starc said.
"He's disappointed, particularly the way he was flying into the summer.
"He was probably first pick in all teams ... Whether it's just purely bad luck or something else, but he still wants to play as much as he can.
"Now that he's not going to the World Cup, I guess he's got a little bit of extra time just to make sure it's right."
Amazon Prime Video exclusively broadcasts all ICC tournaments into Australia, including the current men's T20 World Cup.
