Panthers coach Ron Rivera, speaking for the first time about Newton's surgery, said Monday during the first day of the NFL owners meetings that the top draft pick in 2011 has been dealing with the injury every offseason since he entered the league.
The ankle was aggravated when Newton "nicked" it in a Dec. 22 victory over the New Orleans Saints.
"Every year rest, treatment was part of the rehab program," Rivera said. "This year they went through the program, and when he started working out it just wasn't feeling right, so he went and saw the doctor."
Newton had the surgery on Wednesday. His recovery period is four months, which will take him to the start of training camp in late July. Rivera said Newton could start throwing earlier.
Rivera said he's not concerned that Newton will be out for most if not all of the offseason workouts, even though it means Newton will miss chances to work with a new set of wide receivers.
"There will be a time when they'll get an opportunity to work together, so I'm not worried about that," Rivera said of Newton missing time.
According to team officials, Newton is back at Auburn taking classes toward earning his degree.
Rivera said Newton informed the team while he was working out at Auburn that the ankle wasn't improving as it had in the past. Newton returned to Charlotte about a week before the surgery for an MRI, and the decision to move forward with surgery was made.
"All we know is that every year he's done this, he's rested it, he's treated it and he's gotten better," Rivera said. "This time it didn't get better fast enough, so they went ahead and looked at it."