Harris, 29, was Australia’s most prolific run-scorer in the 2018-19 Border-Gavasker series, punching out 258 runs at an average of 36.9 in a batting order sorely missing suspended superstars Steve Smith and David Warner.With England crumbling to 4-31 at stumps on day three, it is likely Harris will have just one chance to prove himself in the Boxing Day Test – and he took it by compiling an unfashionable yet crucial 76 runs at the MCG.Harris never feared for his place in the line-up because of coach Justin Langer’s staunch support and the left-hander is now expected to bat out the rest of the Ashes.Catch every moment of The Ashes live and ad-break free during play on Kayo. New to Kayo? Try 14-days free now.“I’ve been really fortunate with the support I’ve had the whole summer,” he said.“It can be hard personally when the team’s going well and you haven’t quite contributed like you want to.“Talk starts about your spot in the team, but to be fair to all the coaching staff and selectors have been so supportive, so I haven’t had to worry about that stuff at all.”Harris split his middle finger on Sunday and had to have it glued back together three times, with stitches prescribed for after the Test.And it was Harris who was the glue in Australia’s scratchy innings. In Test No.13, he finally hung around long enough to bat with Smith (No.4).Australia held a first first-innings lead of 82 runs that was almost entirely down to the little opener. Harris posted the highest score in this Test and the second-highest score of his career, but fell 24 runs short of the maiden century he desperately craved.Victorian legend Brad Hodge said a breakthrough century was needed to buy Harris “another four or five Tests” – which would see him safe for the tour of Pakistan in March.“But 70 you’re still on the edge,” Hodge told Triple M.Harris played and missed 20 times and survived a stumping chance on 63, when Jack Leach spotted Harris advancing and darted one leg-side.England wicket-keeper Jos Buttler’s feet didn’t move, a pleasant surprise for Harris after those same legs launched like an Olympian to twice remove him at Adelaide Oval.But former Australian captain Allan Border loved Harris’s application. You sense this was the type of innings Border liked to play.The edges of his came agonisingly close to leather countless times, but when they finally found it there wasn’t much Harris had done wrong.Harris played a Jimmy Anderson peach straight to Joe Root at second slip – but he had to play at it.A false shot it was not. Harris also scored more runs than his first two Ashes Tests combined and he has suddenly made 99 from his past two digs.Facing a new ball on the grassy deck clearly hasn’t been pleasant, but don’t expect Harris to be losing any sleep over Haseeb Hameed, Rory Burns or Zak Crawley’s struggles.Harris wanted to play the ball later because with the ball moving around batters needed as much time as possible.“It’s hard work but it’s probably no different to having to do it over in England, so there won’t be much sympathy for me or probably Davey either,” Harris said.“Over in England and Jofra (Archer) or Stuart Broad, the shoes on both feet. You’ve just got to try and concentrate on the ball and block out the noise as much as possible.“It can be hard when there’s 50,000 people going mental.”Spinner in frame for shock SCG debutGiant killer Cameron Green has earnt membership in the fast bowling cartel, but he’s become so effective he could now take out one of his own.Green has opened the door for Australia’s bold cricket selectors to blood a fourth debutant this Ashes series and hand leg-spinner Mitchell Swepson a long-awaited Test cap in the next Test in Sydney.Josh Hazlewood revealed he hopes to return to bowling this week, but may still be racing the clock to be fit for the fourth Test, while Jhye Richardson (minor foot injury) and Michael Neser (soreness) will also have to be monitored.Despite Mitchell Starc’s stellar Ashes so far, his record in Sydney is average and with a pink ball Test to finish the series in Hobart – and on the back of minimal red-ball preparation for this Ashes – there might be a temptation to try and rest the left-armer at the SCG.Green continued his golden summer with the ball to once again snare the key wicket of Ben Stokes on Boxing Day and make a huge contribution to Australia’s bowling make-up.Four maidens from his first eight overs paint the picture of a nearly two metre tall giant who is genuine bowling weapon.There would be huge benefit in Australia handing a debut to Swepson as a second spinner to partner Nathan Lyon at the SCG ahead of a year where the team will tour Pakistan and Sri Lanka. Brilliant all-rounder Green is the gateway to making that happen, because his wicket-taking ability means Australia could gamble on going in with only two frontline quicks.After blooding Neser, Scott Boland and Alex Carey before the Ashes has even been won, selectors certainly won’t be afraid of picking Swepson as well.“I think it’s really interesting that they (selectors) would have had a look at the next group of bowlers and they’d be thinking, ‘Neser has those attributes, Richardson can do this, Boland can do that,’ but they don’t really know at this level,” said Victorian coach and former Test opener Chris Rogers on SEN.“George Bailey and the selectors would just love to know what the bowlers are going to do when they come out and bowl in a Test match.“You’re finding out intel on these guys as well … I just think it’s perfect for Australia because they really get to see, if in the future they do need some replacements, who are the ones they truly believe in and even for what kind of conditions.”Swepson has been around Australian squads for even longer than Neser without getting a Test match – having first been part of the 2017 tour of Bangladesh.The Queenslander is with this Ashes squad and is set to play a crucial role in Pakistan in the three Test series in March when at least two frontline spinners will be needed.But Australia could benefit from giving Swepson a Test under his belt before he goes to Asia and the pressure is on him to win matches for his team on turning decks.Picking a second spinner in Sydney isn’t possible unless the all-rounder is firing, and provided Green’s workload management is under control, he would be able to give captain and spearhead Pat Cummins the relief he needs to roll the dice on Swepson.Hazlewood (side strain) told SEN he plans to bowl in the nets on day three and five of this Test match to start building his case for a recall in either Sydney or Hobart.