Novak Djokovic will miss the rest of this season because of an injured right elbow.

That means Djokovic will pull out of the U.S. Open and end his streak of participating in 51 consecutive Grand Slam tournaments.

The two-time U.S. Open champion announced the news today, saying “this is the decision that had to be made at this moment.”

Until now, Djokovic has never missed a major tournament since he entered his first, the 2005 Australian Open. That is the third-longest active run among men and seventh-longest in history.

In that time, the 30-year-old Serb has won 12 Grand Slam titles, including at Flushing Meadows in 2011 and 2015.

“The remarkable series has come to an end,” Djokovic said. “My body has its limits, and I have to respect that and be grateful for all that I have achieved so far.”

He said that Andre Agassi, who recently began working with Djokovic on a part-time basis, will be his coach when he returns to the tour next year, starting with a tuneup tournament ahead of the Australian Open in January.

Djokovic’s last match was on July 12, when he stopped playing during his Wimbledon quarterfinal against Tomas Berdych because of the elbow. Djokovic said that day he was in pain when he hit serves and forehands.

At the time, Djokovic said he had been struggling with the elbow on his racket-swinging arm for about 1½ years and so far had opted against having surgery. But he also said then that he would seriously consider taking a prolonged break from the tour.