Newton overturned his vehicle in Charlotte on December 9 in an accident involving a second car and suffered two fractures in his lower back.
A report on the Panthers' website indicated the 25-year-old QB could be fit for Carolina's last game of the NFL's regular season on Sunday, although coach Ron Rivera insisted the key will be how Newton recovers from Wednesday's training session.
"They put him through some very vigorous stuff today to stress him and see how he feels. It'll help us as we go forward," Rivera said.
"Tomorrow will be a big day, especially in the morning, to see where he is health-wise."
But Rivera was clearly impressed by what Newton was able to achieve so soon after his accident.
"I liked what I saw," the 52-year-old said.
"He's progressed. He threw the ball well. He threw a couple deep balls over 60 yards.
"He went through all the drills – everything that we had slated for him."
Carolina can still qualify for the NFL play-offs if they defeat the Cleveland Browns and the NFC South-leaders New Orleans Saints lose to the Atlanta Cardinals in the final round of the regular season.