Incumbent Australia opener Marcus Harris knows his Test spot is up for grabs but he views his lean Ashes series as a positive learning experience rather than a negative.

Harris managed just 58 runs in six innings after coming in for the last three Tests of the series as the replacement for Cameron Bancroft.

He returned from England acutely aware that his spot was in jeopardy for the first home Test against Pakistan in November and that runs in the first four Sheffield Shield matches were needed to maintain his place.

Harris delivered on the opening day of the new season with 116 against South Australia at Junction Oval with national selector Trevor Hohns watching on. But even after his century, he admitted he was still under pressure to keep his Test place.

"I'm not sure there's many spots in the team that's anyone's at the moment," Harris said. "Probably Smithy [Steven Smith] is the only one who has his name written in black permanent marker. So obviously technically it's mine at the moment but I'll have to do quite well to make sure it's mine at the start of the series. A hundred in the first game is probably going to help a little bit."

Harris said he could have easily doubted himself after his Ashes performance, but wants to use it to make him a better player.

"I think it's a great learning curve in hopefully an early part of my career and I can look back on it and learn from it rather than looking at it in a negative way. I'd played in England and done well in all the tour games leading up to the Test matches, so I felt like I was batting really well. It was probably just the level of bowling with the way Broad and Archer bowled.

"I probably hadn't faced too much bowling like that before, and it was probably just the way the ball reacted over there. I wasn't as used to it seaming as far as it did. That was a good challenge. And to be fair it was a challenge for every player in the series besides Smithy. Everyone had their moments in the series where they really battled."

Harris credits Victoria coach Andrew McDonald and his batting coach Lachie Stevens for getting him back on track.

"I spoke to Ronnie [Andrew McDonald] about if I were the only player in the whole series that battled you'd be like 'oh well I've got some serious issues'," Harris said. "But a lot of people battled. So that's why I sort of come out of it looking at it as a great experience, great to be a part of, I didn't do what I wanted to do but it doesn't affect me too much so I can learn from it and use it as a positive."