MONACO -- Top-ranked Jannik Sinner announced he will be out for the rest of the year as he continues to deal with an injured knee.
Sinner has not played since July when he beat Alexander Zverev in the Wimbledon final. He withdrew from the US Open because of a right knee injury.
"Me, together with the doctors, have decided that I need a course of treatment for my knee, which means that the 2026 season is officially over," Sinner said Tuesday in a video message on Instagram. "I also need to think about my long-term career so I will do everything possible to get back 100%."
Sinner risks losing the No. 1 ranking while he's out.
Sinner had already announced he would miss the upcoming Shanghai Masters. Now he'll also miss the Paris Masters and the ATP Finals in November. Plus, he won't be able to play for host and three-time defending champion Italy in the Davis Cup Final 8.
But if Sinner does return at the start of next year, he could play the Australian Open -- the next Grand Slam -- which starts Jan. 17.
"On the advice of his medical team, Jannik Sinner will follow a course of treatment for inflammation in his knee," a statement from Sinner's management team said. "The decision has been made to have the treatment now to give Jannik the necessary time to recover before beginning preparations for 2027."
The 25-year-old Sinner has won five Grand Slam titles. He also had a 30-match winning streak this year before his meltdown in a second-round defeat at the French Open amid a Paris heat wave.
Carlos Alcaraz, Sinner's main rival, missed 4½ months this year due to a right wrist injury.
Meanwhile, Alexander Zverev won two of the four Grand Slam titles and is nearing the No. 1 ranking.