It was a tough hurdle after a bright start to Henry's career at Collingwood, then Geelong, where he had emerged as a dynamic forward and regular goalkicker.
But this September, Henry is back firing, with a career-best 43 goals and a spot locked down as Geelong's forward line head into Friday's semi-final against Fremantle.
"That was one of the things I learned most this year is progress isn't linear," Henry said.
"There's always going to be setbacks, whether that's injuries or just form, and it's how you respond to that.
"And if you can respond to that it's, I think, a good testament of character."
The 24-year-old is reaping the rewards of knuckling down and getting fitter over the off-season.
"I definitely changed a lot. A lot of it comes down to probably just the way I wanted to approach the pre-season and the goals I wanted to hit," he said.
"A lot of that was to do with fitness and especially around my endurance, so I can get to more contests and use more of my attributes more often.
"That's helped me just become the player that I wanted to get back to this year."
Henry had hard, but positive conversations with those around him about finding form again.
"I felt like I'd shown early in my career some of my capabilities as a player, and when you're losing sight of them and not producing, it's sort of like 'how do we get you back to playing that way?'" he said.
'That was all I really needed to spark my belief again and get back on the horse and work really hard at gaining that back."
Henry this year ticked over 100 AFL appearances while he kicked 19 goals - never going goalless - across the past eight games.
"Early in the season I felt like I needed to really prove myself again," he said.
"It takes multiple weeks and adding up of performances and playing your role for your team to feel you belong again and that's just something that I felt like I had to do."
Defender Jack, 28, has watched his brother's resurgence with pride.
"He's just really doubled down on what he's needed to do," Henry said.
"He had a tough year last year, and rarely a player would go through their career without having tough moments.
"For me, I was trying to reiterate that to him, to make sure that he understood that this isn't a permanent thing. It's just it can be difficult at times.
"To be able to bounce back the way Ollie has, I'm really proud of him, and he's had probably I'd say one of his best years to date.
"So hopefully he can just keep improving and keep the confidence up after this year, and keep going."
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