Carlos Alcaraz makes more history at the Paris Games with a semifinal victory in straight sets over Félix Auger-Aliassime. (0:59)
"That's going to be, obviously, the biggest challenge that I can have at the moment," Djokovic said taking on Alcaraz, who also won the French Open in June at Roland Garros, the same clay-court facility being used for these Olympics.
Serbia's Djokovic, 37, is the oldest man to reach a men's singles final at the Olympics; Spain's Alcaraz, 21, is the youngest.
Djokovic got injured during the French Open, tearing the meniscus in his right knee and having surgery on June 5. He felt what he described as "sharp pain" while getting past Stefanos Tsitsipas in the quarterfinals Thursday night, but he seemed fine against Musetti.
Djokovic went into that semifinal with an 0-3 record in that stage at the Games, losing to the eventual champion each time: Rafael Nadal (Beijing), Andy Murray (London) and Alexander Zverev (Tokyo). Djokovic mentioned that "hurdle" repeatedly the other day and again Friday night.
He acknowledged feeling nervy and seemed that way, bothered by things such as the wind or the footing or the chair umpire calling him twice for time violations and then warning him for an audible obscenity. Over and over, Djokovic would gesture at his team up in the stands, muttering or even yelling.
But his tennis was on point, other than when he got broken to begin the second set. Still, he quickly regrouped and took six of the last seven games.
That's the only thing missing from his remarkable résumé, which is filled with accomplishments such as 24 Grand Slam titles and more weeks ranked No. 1 than anyone else.
Djokovic has spoken often how much it means to him to represent his country and how much he wishes he could do better than the bronze he picked up in 2008.
Alcaraz already owns four Grand Slam titles and is a month younger than Vincent Richards of the U.S. was when he claimed the gold in Paris in 1924.
The contributed to this report.