Burkholder has treated Charles like a burn victim, using burn dressings and covers on his feet and toes.
A blister developed on the ball of one of Charles' feet this week, prompting the team to use UltraViolet light to kill any infection and electrical current to stimulate skin growth.
Charles also is wearing socks that many marathoners and triathletes wear to fight friction and reduce moisture.
Despite playing with pain and not being able to cut with his usual crispness, Charles had maintained production over the past two games, gaining 272 yards from scrimmage and scoring two touchdowns over that stretch.
Charles, 26, entered Sunday as the NFL's sixth-leading rusher with 397 yards this season. The two-time Pro Bowler rushed for a career-high 1,509 yards last season.