Having taken up cycling a year ago, the 38-year-old was recruited via an online training programme and features in an outfit boasting triple world champion Pauline Ferrand-Prevot and former time trial world champion Lisa Brennauer.
Thorvilson, who quit long-distance running after injuries ruined her career, beat more than 1,200 women in a series of virtual rides in a Zwift Academy initiative last month.
The project with the team's partner Zwift, the online social fitness platform for cyclists, aimed to search for talent with non-conventional methods and offer a professional contract.
The competitors faced a series of structured online workouts and tests. Narrowed down in the semi-final stage to 12 women, training became a combination of indoor and outdoor sessions.
Thorvilson was one of three finalists called up to the Canyon-SRAM training camp for a 10-day final in Mallorca, Spain, where she was selected to join the team.
“We felt like outsiders but not because they (the team riders) were being rude. They were in their training camp and we were just invited,” Thorvilson said.
“I was just wondering, do they even take us seriously? They did not give me any reason to think that they did not want us, and I feel more included now than then.”
The rider from Little Rock, Arkansas, was not sure she had what it takes to become a professional cyclist but there was no reason she should not try.
"I knew I had an engine just from running and I knew I had the dedication but when I started I didn’t know if I had thought about racing (competitively),” Thorvilson, who ran the 2012 Olympic Team marathon trials, told Reuters by telephone.
"I had three consecutive surgeries on my right knee and I was told I was possibly done running forever. I knew I had to do something different, I decided I was going to get a bike.
“Twelve weeks after my final surgery, in February 2016, I could start cycling just on a stationary bike and some friends of mine told me right when I got my trainer, that (the indoor cycling software) Zwift had a competition. I thought why not enter, I had nothing to lose.”
She won and was offered a one-year contract with Canyon/SRAM team manager Ronny Lauke, saying: "Although from a power output Leah was the strongest, it has not been the only factor to play a role in her selection.
"It was her curiosity of what to expect next, how to do it best in training every day, and also the continued positive spirit after some setbacks that made us believe we can have the most impact on her further development.”
Thorvilson is still amazed to have been offered a deal but also knows she is on a steep learning curve.
“I still don’t know if that (winning) has sunk in. I felt like I had too far to go. I know I’m strong but have a lot of work to do to get my technique to match the levels of my fitness and my power.
“The team know I have a long way to go but I’ve just started. They were willing to take that chance I hope I don’t let them down,” added Thorvilson, who made her debut in a small local race in Australia as she is still getting to grips with riding in a peloton.
“They know it was much smarter this way than to put me with girls with experience. I have never been in an aggressive race field at that level.
“I would love to race (in the top races) and it’s hard to fathom them selecting me (for these races) but, on the other hand, I don’t think they took it on (the Zwift initiative) thinking I would not ride,” she said.