Hegerberg tore off his cruciate ligament in early 2020 and then also suffered a stress fracture in his tibia and has not played football since.
After three operations, she is now finally back in training with her teammates.
The club tweeted "Hello, hello Ada" on Monday and showed a clip with her together with the teammates.
It is unclear whether the 26-year-old is ready to play for Friday's home meeting with Guingamp in the French league.
In 2018, Hegerberg, as the first woman, received the Ballon d'Or as the world's best player and she has scored an incredible 144 goals in 117 matches in Lyon.
Hegerberg has also been noticed for boycotting games in the Norwegian national team.