Adams has not thrown beyond that mark since beating Schwanitz with a throw of 20.88m at the 2013 world championships. China's Lijiao Gong and American Michelle Carter have also surpassed 20m this season.
Last year, Adams' dominance of her discipline saw her become the first female thrower to be awarded the IAAF world governing body's athlete of the year. She set eight of the 10 best throws in 2013 and 2014.
Adams told the Herald she is anxious to succeed and the competitive instincts have returned.
"I've competed many times against Christina. She's thrown well this year, but she hasn't come up against me. Tomorrow it will be great to go up against her, Gong and Carter.
"It's great to see that level of competition. It shows the standard has gone up. The level hasn't been too flash the last couple of years. Hopefully I'll be right amongst them.
"However, there is a bigger picture to look at than tomorrow. That means defending my titles at the world championships and the Olympics."
The elbow operation required moving the ulna nerve from the bottom to the top of her right forearm. That meant cutting a hole through the muscle to thread through a tendon she described as "pretty much rotten". The nerves had to repair millimetre by millimetre over months.
Adams said she had fully rehabilitated with the help of her career-long physio Louise Johnson. The process had been daunting given she has never missed a season since starting professionally in the early 2000s.
"As an athlete we experience pain on a daily basis, but I'm ready to start competing. We're pushing our bodies to the limit and they're not made to be pushed like that on daily basis, Lou adds the 'feel-good' factor through the likes of ultra-sound and soft tissue massage. If she can put a band aid on it and keep things going, that's good enough for me.
"However, it takes longer to warm-up, I use a lot more strapping and I rub a lot more hot stuff on my body. Once I could just turn up and start jogging. Now I need more tape and cream."
Adams brought a brave and charismatic tone to her press conference at the athletes' hotel in the shadow of the Eiffel Tower. The inability to throw a tennis ball post-surgery was scary.
"The hardest moment was not knowing if I could throw again during the recovery. I had to accept it was going to take longer than I thought. The nerve takes a long time to grow. When it is your throwing arm, that's your whole life."
In May, Adams told the Herald she could see her Olympic dream literally slipping through her fingers.
At the lowest point, a couple of her fingers wouldn't respond to the simplest of tasks. It led to momentary doubts about her future as she chases an unprecedented New Zealand feat next year - the prospect of winning gold medals at three consecutive Olympic Games.
"The ring finger and pinky on my right hand were such that I couldn't pick up the phone, cut my fingernails or scratch my hair because I had no strength. It was more difficult because it was my throwing arm. The nerves, muscles and ligaments wouldn't respond."
"The trust and confidence is now back but it was weird having to see people like hand therapists. As a thrower, I'm used to doing things in big loads but I was reduced to awkward little stretches, a situation I hadn't faced before."
Adams wasn't tempted to insure her arms in the aftermath.
"I'm not American," she quipped. "God's given me these parts, these genes and these talents to use as well as I can. I don't regret having four surgeries in one year; that's part of the territory.
"There's high tension and a lot of nerves, but I'm anxious to get into the swing of things."
She held one regret about competing on Saturday; she also wants to be in Tonga, the homeland of her mother, for King Tupou VI's coronation.
"I'll be following on social media and the internet," Adams said. "It's a special day for every Tongan around the world. The Queen is also from [Adams' mother's village] Houma, which makes it more special."
