A normal recovery period from surgery for an ACL tear is 9-12 months, but Kerr spent a frustrating 18 months out of the game before making her highly-anticipated return in September.
A problem with a surgical graft that went undiscovered for 10 months was the reason behind the extended recovery period, but Kerr is back firing ahead of Australia's Asian Cup opener against the Philippines in Perth on Sunday.
The 32-year-old Chelsea star fronted the media on Saturday and reflected on her "long and hard journey" to be back in full flight.
"It's kind of come in waves," Kerr said.
"I think at the start when I came back from the ACL with Chelsea at the start of the season I felt really good.
"And then I probably had a little bit of a dip, and then I felt from December onwards, when I started scoring a few more goals and just feeling relaxed and confident in my ability again, I started to really feel at my best.
"I feel like I'm just trying to get my confidence back. When you're out for so long, you kind of have all this self doubt creep in and all of that.
"But I've had so many amazing people around me, and I feel right at home with the Matildas, so it's a good place for me to just settle back in and be myself."
So where is she on a scale of one to 100 right now?
"I feel like I'm probably 85 and above," Kerr said.
"I don't want to say I'm at 100 yet. I haven't had one of those games yet where I felt completely myself, but I think about 85 per cent and above."
The Matildas have won the Asian Cup only once - back in 2010 when Kerr was just 16 years old.
Kerr is the only remaining member of that squad who is still playing.
"That makes me sad that I'm the last one standing," Kerr said.
"Still to this day, that is one of the best moments in my footballing career.
"And I know how much this team wants to win something together. I know how much every player wants to win something for the Matildas."
Matildas mania swept Australia during the team's run to the semi-finals of the 2023 Women's World Cup on home soil.
Kerr tore her left calf on the eve of that tournament, and then injured her right calf in the third-place play-off loss to Sweden.
"I'm just really looking forward to being in a tournament and not talking about my left calf," Kerr joked.
"I've had a long journey from my ACL return, so I'm just honestly so excited, so grateful to be back here and just be playing football, enjoying training, enjoying all the things that come in, come with the team.
"Obviously, the last tournament didn't go the way I wanted personally, but on a team level it was an amazing tournament.
"So I feel like I'm just really lucky to be here again at a major tournament on home soil.
"Most people in their career don't get to play one home tournament at home. So the fact that we get two opportunities is an incredible honour."
There are plenty of fitness doubts for the Matildas heading into the tournament.
Mary Fowler has played just two games since making her own return from an ACL tear, goalkeeper Mackenzie Arnold has been barely sighted on the training pitch and is in huge doubt for Sunday's opener, while Arsenal midfielder Kyra Cooney-Cross was a no-show at training during the open part of the session on Saturday, raising doubts about her availability.
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