However Serbia's team left open the possibility that he could be replaced if he is too tired upon his return from New York.
"Nole is coming back today, we will see how he will feel and whether he will be ready," said No. 16-ranked Viktor Troicki, who is expected to replace Djokovic if needed. "If he is not ready, I am."
Djokovic was not present for Thursday's draw at the Belgrade Arena. Davis Cup officials said Djokovic has been held up in New York and will join the team later.
Djokovic last year led Serbia to its first ever Davis Cup title.
Serbia's team captain Bogdan Obradovic said Djokovic still needs to assess his condition, but he added: "Novak does not even need training here, just that half an hour before the match. So huge is his confidence, we can all feel that."
Last year, Djokovic pulled out of the opening match of the semifinal against the Czech Republic because he needed rest after the U.S. Open where he lost to Roger Federer in the semifinals. Troicki was a late replacement for Serbia on the opening day, while Djokovic played the reverse singles.
This year, Djokovic beat Rafael Nadal on Monday in a match that lasted more than four hours, to win his third Grand Slam title this year. He also won Wimbledon and the Australian Open, but lost in the French Open semifinals.