Djokovic later posted a statement on Instagram.
“This whole situation has left me really sad and empty,” he wrote. “I checked on the lines person and the tournament told me that thank God she is feeling ok. I’m extremely sorry to have caused her such stress. So unintended. So wrong.
“As for the disqualification, I need to go back within and work on my disappointment and turn this all into a lesson for my growth and evolution as a player and human being … Thank you and I’m so sorry.”
Carreno Busta said in his press conference that he did not see the incident in question.
“I didn’t watch the moment when he threw (hit) the ball,” the Spaniard said.
“[I was] looking to my coach, celebrating the break and when I turned back again the line umpire was on the floor.
“I’m very apprehensive with this kind of thing. I asked the Colombian guys in the crowd if the ball hit the line umpire and I was in shock. I never expected this moment. It was a tough moment also to me.
“When they were talking on the net, I tried to be focused if the case was that we have to continue playing.
“In one moment I asked the referee what’s happening because it was so long to me, this moment. It was 10 minutes I think. So I needed to be ready if we have to continue.”
Carreno Busta will now face the winner of the match between Denis Shapovalov and David Goffin. Three-time US Open champion Djokovic was the clear favourite at Flushing Meadows in the absence of Roger Federer and Rafael Nadal and was yet to drop a match this year.
Jordan Thompson and Alex De Minaur had ensured two Australian men will be in the fourth round of a tournament now guaranteed to have a first-time grand slam winner. Thompson, however fell in straight sets to 27th seed Borna Coric on Monday. He lost 7-5, 6-1, 6-3 to leave De Minaur flying the flag.
The United States Tennis Association issued a statement soon after the incident.
“In accordance with the grand slam rulebook, following his actions of intentionally hitting a ball dangerously or recklessly within the court or hitting a ball with negligent disregard of the consequences, the US Open tournament referee defaulted Novak Djokovic from the 2020 US Open,” it read.
“Because he was defaulted, Djokovic will lose all ranking points earned at the US Open and will be fined the prize money won at the tournament in addition to any or all fines levied with respect to the offending incident.”
Australia’s Nick Kyrgios, another star to skip the tournament due to coronavirus concerns, took to Twitter to ponder the likely reaction were he to have been in Djokovic’s shoes.
“Swap me for jokers incident,” he wrote. “‘Accidentally hitting the ball kid in the throat’ how many years would I be banned for?”
One man who stands to benefit from Djokovic’s absence, Alexander Zverev, sympathised with his rival.
“It’s very unfortunate that he hit a line judge and especially where it hit her,” the 23-year-old German said.
“There is a rule in place for it. I think the supervisors are just doing their job but very unlucky for Novak, I think he’s going to be a little bit upset about it.
“If you would have hit it anywhere else, if it would have landed anywhere else – we were talking about a few inches – he would have been fine so very unlucky.”
The fifth seed slammed down 18 aces en route to demolishing Alejandro Davidovich Fokina 6-2, 6-2, 6-1.
Upsets were the order of the day in the women’s draw. Unseeded American Shelby Rogers eliminated sixth seed and dual Wimbledon champion Petra Kvitova 7-6 (7-5), 3-6, 7-6 (8-6), fighting off four match points to make the last eight at Flushing Meadows for the first time.
Seventeenth seed Angelique Kerber, meanwhile, was bounced out in straight sets by American 28th seed Jennifer Brady, while Petra Martic, the eighth seed, fell in three to No.23 Yulia Putintseva.
The round-of-16 match between Naomi Osaka and Anett Kontaveit will wrap up the Sunday night schedule from the US.
with AP, Reuters
James Polson is a sports desk editor with The Sydney Morning Herald.