Six months after becoming the first Brit to be crowned all-around European champion, the 19-year-old was struck down by an ankle injury and underwent surgery in the summer of 2017.
Ellie revealed just how vital the support of older sister Becky, a double continental champion herself, was in a recovery she thought impossible.
"I remember the middle of last year sitting down with Becky and my ankle was really sore to tumble on. That was the worst thing," said the Nottingham-born star.
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"And I just said to her: 'I don't think I will ever be able to tumble again like I could.' That was obviously disheartening, and I never thought I would."
"Becky got injured at the same time as me pretty much, she hurt her elbow at the Europeans where my ankle got sore.
"We could kind of help each other and push each other through our rehab and it was great to see our progressions. When we both finally made it back it was a really nice moment.
"It is nice to be in training and not take things for granted. Days when I am tired I think back to when I was injured and wanted to do this work. That motivates me.
"It would mean the world to be at Tokyo, I can't really put it into words."
"I think if I get there I will just be really really excited, more than nerves or anything else. The year and a half in this cycle was so rough that I am going to appreciate every moment I get like that."
Downie broke out at the 2014 Youth Olympics, bringing back a competition-high four medals from the mats in Nanjing, China and was named Young Sports Personality of the Year in 2015.
The Olympics hold mixed memories for the Midlands product who reached the all-around final in Rio and finished 13th, while coming fifth under the British banner in the team competition.
After spending nearly three years of the Tokyo cycle in rehabilitation, Downie returned to action in inimitable style at this year's British Championships.
Despite claiming triple gold at the nationals and bringing back silver and bronze from the European Championships in April, simply competing is salve enough with the Olympics less than a year away.
"Through my injury, it was a very hard and quite a sad time. No one likes to be injured and it just kept coming and coming," she said.
"I never felt like I was going to get back to what I was, but the start of this year I feel like I am back where I want to be and can progress from that.
"It is great to be back in the mix, going to competitions with the girls again and being part of the team again.
"This year just before the British champs was the first time I did my whole old floor routine with all the hard tumbles in, it was just such a relief.
"I wasn't even competing it, just doing it in the gym was amazing.
"Then being able to go out there and compete it successfully so many times this year already makes me feel really grateful for everything I have already done.
"I don't put pressure on myself anymore because I know where I was and to get back here is just unreal."
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