Slye and Scott were deemed at risk after being in contact with another person who tested positive for the coronavirus. They were quarantined from the facility beginning on Monday, when players, coaches and staff members were asked to work remotely for two days.
They were eligible to return after five days of testing negative.
Being placed on the list means a player has either tested positive or been in contact with somebody who has the coronavirus.
Getting Slye back was significant because the Panthers (3-3) had to bring in three untested kickers just in case he wasn't available.
Douglas becomes the fifth Carolina player to go on the COVID-19 list since last Friday. Backup guard-center Tyler Larsen went on the list a week ago. Guard Michael Schofield was added to the list on Monday, followed by Slye and Scott on Wednesday.
Carolina remains in the intense protocol, which requires teams potentially exposed to the coronavirus to implement additional precautions.