Injured fast bowler Peter Siddle says selectors would be taking a "massive" risk by recalling one of James Pattinson or Pat Cummins to replace Mitchell Starc on Australia's Test tour of India.

The Victorian believes the two quicks, both on the comeback trail from injury, are in a two-way battle to take Starc's spot in Australia's touring party after the left-armer headed home on Friday due to a fracture in his right foot.

Quick Single: Starc injury a huge blow to Australia

Starc's absence is a massive blow to Australia's chances of retaining the Border-Gavaskar Trophy and Siddle believes Pattinson and Cummins are the only two viable replacements who possess the same raw pace that makes Starc so dangerous.

But the fact that the duo are both in the early stages of their comebacks to first-class cricket has Siddle worried that a Test recall would be pushing them too hard too soon.

Starc sent home due to foot fracture

"I think they want a bit more genuine pace so it probably comes down to Cummins and Pattinson," Siddle told Fox Sports.

"They're two blokes who at this stage you were probably hoping you wouldn't have to call upon. It's going to be a tough call.

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"Ideally, I don't want either of them going because I'd like them to play some more cricket, but they're going to take one of them."

The two right-armers put their names forward this week with stellar performances in the Sheffield Shield; Cummins bagged eight wickets in his first Shield match in almost six years, while Pattinson grabbed three quick wickets on a unresponsive surface in Alice Springs on Friday afternoon, displaying impressive pace and noticeable reverse swing.

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While the pair played limited-overs and Second XI cricket before their Shield comebacks earlier this year, both had been targeting a Test comeback in the Ashes next summer, keen to take a conservative approach having broken down when they rushed previous comebacks from injury.

Siddle, who himself is currently sidelined until next season with a serious back injury having pushed himself to be fit for the Perth Test last November, said selectors would be taking an obvious risk by recalling one of the young quicks so soon.

"It's massive," he said. "One good factor is that there's not a lot of cricket this winter, so if anything does go wrong there's not much missed.

"But if it's a big injury then it's a lot to take in.

"Jimmy and Patty have played a fair bit of cricket now, just not as much as they would have liked to probably be comfortable to go over there and perform.

"They're not super underdone, but they're probably not at the point where they're ready for Test level. But those guys will definitely stand up if the opportunity arises."

Pattinson roars into life in Alice Springs

No matter who replaces Starc, Siddle believes the left-armer's absence is a huge setback for Australia's chances of winning the four-match series in India.

The dominance of Australia's spinners in the opening two Tests has meant Starc has taken just five wickets, but all have been crucial top-order breakthroughs that have paved the way for more wickets to follow.

Siddle says Starc's absence means fast-bowling partner Josh Hazlewood as well as spinners Nathan Lyon and Steve O'Keefe, who have all impressed so far in the series, will have to step up to another level.

"I'd like to say no, but there is a little bit of pressure on the rest of the group now," Siddle said when asked if Starc's absence means Australia can no longer win the series.

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"I know (Starc) hasn't taken the ... wickets that he has in the past, but I think he's done a great job at the other end to build pressure for those guys to take wickets.

"Josh stepped up in the last Test match and hopefully he can continue on now with that form. The spinners have been very good. Those three are going to have to combine really well.

"Who comes into the side now? I'm hearing Glenn Maxwell will probably play as the allrounder for Mitch Marsh, but (the replacement for) Starc I'm not so sure.

"Jackson Bird is there but they'd be definitely flying someone over to replace him."