Cameron Green's Ashes series is in jepoardy of being over after just a single day of Mitchell Marsh being back in the side.

The news that Green had suffered an injury forcing him out of the Australian side heading into the third Test at Headingley was met with plenty of trepidation from Australian fans, and with good reason.

Green has been, whether rightly or wrongly, carrying out a tag that labels him the future of Australian cricket for the last 12 months.

And some of his performances have well and truly backed that up with both the bat and the ball. There is little doubt that Green will, at some point, reclaim his point in this Australian side and have a long, successful career in the baggy green, and, as a matter of fact, across all three formats for Australia.

His aggressive yet technical style with the bat is matched by a strong ability with the ball, where his height makes him a real threat. That is, of course, despite injuries over the first part of his career which often see his impact with the ball in the Australian side well and truly limited as a protective measure from captain Pat Cummins.

Reports out of the Australian camp indicated that Green's "low grade" hamstring strain will only sideline him for a single Test, with a lengthy break in between the end of the third at Headingley and the start of the fourth at Old Trafford.

But there is now a real question of whether he will regain his spot in this side.

Mitch Marsh travelled to England with the Test squad knowing that, while he is a fixture of Australia's white ball teams, he was a back-up option in the red ball one.

But that quickly turned into being needed for the third Test, and thrust into an exceptionally difficult situation.

Asked to bat first, Australia lost wickets early and regularly on the first day. David Warner, gone in the first over for four, was followed at 2 for 42 by Usman Khawaja, with Marnus Labuscaghe and Steve Smith following not longer after.

Australia quickly found themselves reeling at 4 for 85 when Marsh came to the crease, joining Travis Head.

Instead of poking around and trying to fight the hard way though, Marsh took the attack to the Australians, turning the usually aggressive Head into the partnership's anchor.

He and Head would put on 155 for the fifth wicket, with Marsh scoring 118 of those at a run a ball, with an emphatic Test century on his return.

He then backed it up with the ball, sending down three overs to wind up with a vital wicket, getting rid of Zak Crawley in the final half hourt of the day. The English opener, had, until that stage, been controlling the game with 33 from 39 balls the final result.

Ultimately, it was a day dominated by Marsh, with a century out of 263 and the vital wicket of a set batsman leading up to stumps.

But it now begs the question - with Green likely fit again for Manchester, how do you drop Marsh?

The short answer, really, is you don't.

You can't drop someone fresh off a century, particularly when it would be for someone who has not exactly set the world on fire so far this series.

In the first two Tests of this year's Ashes series, Green has scored just 38, 28 and 18 to go with a duck, while he has taken combined figures of 3 for 171, albeit on fairly docile wickets.

Add to that, Green managed scores of 6 and 25 in the World Test Championship final to go with 2 for 44 and 0 for 13, and it becomes exceptionaly hard to mount a case that he should return.

If he does, it certainly won't be for Marsh, who should at least play the fourth Test, and possibly the fifth back in London as well.

That means for Green to play, Australia would need to go with two all-rounders, but there realistically is no one else to replace, unless they decide Green could open - which would appear out of the question.

Even then, veteran opener David Warner - who made 66 in the first innings against a swinging ball at Lord's - has done enough to keep his spot.

Usman Khawaja, Steve Smith, Marnus Labuschagne and Travis Head are all undroppable, meaning it's a straight shootout between Marsh and Green.

Right now, on intent, experience, and form, Marsh has the running to hold the spot.