The French doubles specialist said on Tuesday that the victory against the third-ranked Serb at the Masters in Paris earlier this month was a confidence booster.
France captain Guy Forget said he will decide who will play ahead of the draw on Thursday.
Llodra said "I'm ready, but it's up to Forget to decide" who will start in the singles on Friday.
Jo-Wilfried Tsonga was ruled out of the December 3-5 final with a knee injury, leaving Llodra to compete with Gilles Simon for a singles spot alongside Gael Monfils.
Serbia is seeking its first Davis Cup title against nine-time champions France.