Thorne suffered a cruciate ligament injury in January, but after returning to training two weeks ago, the England Under-19 international has revealed that his comeback is going to plan.
The 20-year-old told the Birmingham Mail: "I've been back in full training for two weeks or so and it gets easier each day.
"It's good to be back. For the first couple of days, it felt a bit weird. You lose your instincts and I was over-thinking everything. I'm back into my rhythm and I feel alright now.
"It's just a matter of getting more sessions in and getting the fitness back up. It was difficult when the lads came back in and the season started to approach. But it's been good since I got back into training and it's been happy days since."
Thorne has made 14 appearances for the Baggies, while also spending loan spells at Portsmouth and Peterborough United.