Novak Djokovic has pulled out of the ATP Finals with a shoulder injury, shortly after winning his 101st career title, organisers said on Saturday.
The 38-year-old will be replaced in the Jimmy Connors Group by Lorenzo Musetti, who was beaten by Djokovic in the final of an ATP event in Athens.
Djokovic, a record 24-time Grand Slam winner, had been set to face Carlos Alcaraz at the season-ending Finals, which start on Sunday in Turin.
Djokovic had long since qualified, but kept everyone guessing until earlier this week about his participation in the prestigious tournament.
On Tuesday the head of Italy's tennis federation Angelo Binaghi said that Djokovic had confirmed that he would play at the Finals.
Djokovic withdrawing is good news for Musetti, who had previously needed to beat the Serb in Athens in order to snatch a spot at the Finals from Felix Auger-Aliassime.
Now the Finals will have two Italians for the first time with defending champion Jannik Sinner in the Bjorn Borg Group with Auger-Aliassime, Ben Shelton and Alexander Zverev.