Who's missing from 2021 US Open: Defending champion Thiem, Federer, Nadal and Serena Williams among leading names

Unlike the 2020 edition of the US Open which was blighted by the bubble scenario and the return of tennis after Coronavirus, the list of names missing from this year's tournament isn't as widespread but the star attractions are.

As has previously been reported, it is the first time since 1997 that Rafael Nadal, Roger Federer and Serena Williams will all not play at a Grand Slam marking a spell of 24 years which shows an almost changing of the guard starting to emerge. We run through those main names missing.

Not as big an announcement as the absences of Serena, Nadal or Federer to some but it marks another year on either the men's or women's draw that the defending champion will not take to court.

Last year, it was Bianca Andreescu on the Women's side due to injury as well as Rafael Nadal on the Men's side. That means none of the defending champions on the men's side since 2018 when Novak Djokovic won it are in action.

An injury has paid heed to Thiem's plans for a return. Sustained during the Mallorca Championships, he has a wrist injury which had a setback. This meant his season was over.

A theme is injuries and for Rafael Nadal, it was the same but one that has gone on for some time. A left foot injury saw him pull out of Toronto after he avoided Wimbledon and the Olympics seemingly to get ready for the US Open.

He returned to much fan fare at the Citi Open Washington but Lloyd Harris took him out and he was set to face the South African again before his withdrawal.

But the signs were there that Nadal wouldn't compete with entry into a golf tournament back home and going seeing a specialist. He won't compete again this season either.

The Swiss legend was the next to do so as he suffered a setback himself with his knee at Wimbledon.

Reaching the latter stages, he showed glimmers of his old self but also looked laboured and decided against the Olympic Games as a result.

But it seemed that he needed yet another knee surgery so will miss the rest of the year at least as he goes back to square one after his previous surgery.

News dropped earlier this week about the Williams sisters being the latest to also withdraw due to injury with Serena's hamstring injury suffered at Wimbledon not allowing her to play.

She did so on medical advice after not playing during the warm-up tournaments either so the doubts were there.

While in terms of Venus Williams, she actually played in Chicago earlier this week losing to Su-Wei Hsieh but a leg injury which she has been battling for some time as she dubbed couldn't produce miracles this time.

Still though despite withdrawals, on the men's side, it is still highlighted by Novak Djokovic still continuing his Calendar Slam quest, Alexander Zverev, Stefanos Tsitispas.

While on the Women's side, top stars Ashleigh Barty, Naomi Osaka, Bianca Andreescu, Aryna Sabalenka and Victoria Azarenka among others will compete at Flushing Meadows.