With Rafael Nadal ending his season due to a foot injury, and Roger Federer about to undergo a third surgery on his knee, the 2021 US Open will be just the second Grand Slam since 2000 where neither of the two 20-time major champions are in the draw.

The only other time was the 2020 US Open, which Federer missed due to the same right knee injury and Nadal sat out of due to travel concerns.

Dominic Thiem went on to win his first major at the 2020 US Open—coincidentally, the Austrian has pulled out of this year’s US Open as well, with a wrist injury.

Before the 2020 US Open, the last Grand Slam that didn’t feature either Federer or Nadal in the main draw was the 1999 US Open, where Federer fell in the second round of qualifying and Nadal hadn’t started playing professional tournaments yet.

Novak Djokovic will go for two big pieces of history in Flushing Meadows this year. Not only will he try to become the first man to complete a Calendar-Year Grand Slam since Rod Laver in 1969, he’ll also be going for his 21st career Grand Slam title, which would break a three-way tie with Federer and Nadal for the all-time men’s record.