Doug Sloan

Doug was a CTU agent active during Day 2.

Day 2
As Jack Bauer and Ed Miller escorted Nina Myers to Warden Airport, Jack secretly drugged Ed, who passed out. Fearing for her safety, Nina shouted to the agents who were waiting at the plane about Jack's actions. To her dismay, Agent Doug was part of Jack's plan, and Jack thanked him for his assistance.

FBI Agents Rick Phillips and his partner Harris were also at the airport and knew that Jack drugged Miller. It is possible that Agent Doug informed them, since Jack did not.