CHARLOTTE – Quarterback Cam Newton (shoulder), defensive end Charles Johnson (back) and wide receiver Damiere Byrd (knee) are undergoing surgical procedures that will sideline them during the Panthers' offseason practice program. All three are projected to return to action for the start of training camp.

Newton is having surgery on his throwing shoulder at Carolinas Medical Center on March 30. The injury occurred against the San Diego Chargers in Week 14 of last season. Newton finished the game, and the following week, an MRI revealed a partially torn rotator cuff.

"It is well-documented and well-researched that overhead throwing athletes commonly have wear and tear to their rotator cuffs," head athletic trainer Ryan Vermillion said. "As a result of the MRI, we modified all of Cam's work in the weight room and on the field for the final three weeks of the season."

Newton did not miss any snaps in the remaining three games, and after the season concluded, a number of MRIs were performed to monitor his progress. Newton also saw a rehabilitation specialist in Atlanta who was in daily contact with Vermillion.

"We developed a plan for Cam to take a period of rest, a period of rehabilitation and treatment, and then start a gradual throwing program the first part of March," Vermillion said. "Cam started his program, and the early parts of his rehab had been going well. However, as we worked to advance him into the next stage – the strengthening stage, the throwing stage – he started to have an increase in his pain level and started having pain while throwing.

"As a result, Dr. Pat Connor (head team physician) felt the most prudent procedure would be to arthroscopically repair the shoulder."

Newton has missed just three games in six NFL seasons. He underwent ankle surgery prior to the 2014 season, which is the only other the time he's been unavailable for OTA and minicamp practices.

Newton has been working out throughout the offseason, and head coach Ron Rivera and general manager Dave Gettleman have indicated he's in tremendous physical shape. Following surgery, he will begin rehabbing the shoulder while continuing to condition his body for the 2017 season.

"The thing we need to stay away from the most is throwing, but he will start immediately with range of motion and rotator cuff exercises," Vermillion said. "The positive thing, unlike when he had ankle surgery, is that he will still be able to work on his conditioning, work on his core, work on the rest of his body.

"Twelve weeks following surgery, Cam will begin an early throwing program with me. If he progresses well he will start throwing with the team at 16 weeks after surgery and we'll go from there. Our goal is to have him back at the start of training camp."

Johnson, who is entering his 11th season, alerted the athletic training staff of back pain recently, which ultimately led to surgery at Carolinas Medical Center on March 21.

"We began a normal course of action and treatment. He saw Dr. Connor, we did an MRI, and Charles received an epidural injection," Vermillion said. "Unfortunately, he didn't get much relief from the injection and progressively worsened over the next few days. He saw Dr. Bruce Darden at OrthoCarolina, and we felt the best course of action was for Charles to undergo a microdiscectomy.

"Following surgery, we want Charles as active as possible while still taking the proper precautions. He will be up and moving around the next day, and we will progressively bring him back."

Byrd, who made his NFL debut in the 2016 season finale, injured his left knee while conditioning on his own according to Vermillion.

"We saw him for treatment, but he continued to experience pain and swelling," Vermillion said. "An MRI revealed he has a torn lateral meniscus in his left knee, and Dr. Connor will perform a scope on his knee. We will modify what he does in our conditioning program, and he's projected to be ready to go later in the offseason."