He could run but couldn't do much else, and getting back to full-time footy felt a long way off.
"It was a bit disheartening," Aish told AFL.com.au's Prime Prospects series.
Things sped up from there. He started to get into tackling drills, moved into match simulation, and started to feel like himself again. The shoulder, Aish says, has been no trouble since returning to the field last month.
"I'm really confident in my shoulder now in games. I don't really think about it at all. By my first game, there were no issues there," he says.
But the challenges haven't stopped. Throughout the NAB AFL Under-18 Championships, the South Australian was tagged heavily.
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Opponents got in his way, stood next to him at stoppages, bumped, niggled and nagged him, and did what they could to stop him getting the ball.
And it also happened at SANFL level when he returned to play for Norwood, where he played a starring role in its premiership last season.
Aish had been matched-up closely before – he's been a highly touted draft prospect for many years. But not to that extent.
Without much match practice, he found it hard to get into games, and harder to find space, run with the ball and make the play. Aish has put some thought into how to beat the attention.
"It's an obstacle to get over. In some aspects it's good to have it now, and I'll have to be mentally strong, and work harder, and improve other areas. But it's still frustrating at the same time," he said.
"I'm still learning. I've talked to a lot of people about it. I've been lucky to talk to a few AFL players and they've given me a few little tips. I think it just comes down to work ethic.
"I have to push myself harder forward and back to get some touches, and you can look at defensive strategies and other ways to get into the game.
"Back at Norwood I've talked to a few of our inside midfielders, and we're going to try to come up with a few tactics later in the year if it was to occur again."
Aish played every game of South Australia's championships-winning carnival, and averaged 15 disposals at 87.3 per cent efficiency, the best of any player. He was named an All-Australian for the second consecutive year.
The 17-year-old wingman plays in a traditional way. He runs up and down the ground, delivers the ball, sets things up, and occasionally starts on a flank. Aish rarely appears rushed, and thinks through situations when he is.
As part of the AIS-AFL Academy, Aish last week lived with Gold Coast captain Gary Ablett after spending a week training with the Suns. It was another experience preparing him for the future, a future likely to take him out of South Australia come November's draft.
"It is a bit strange and surreal that it's just around the corner, really," Aish said. "It's only a few months away and then hopefully a new chapter of my life starts."
Callum Twomey is a reporter for the AFL website. Follow him on Twitter: @AFL_CalTwomey.
