Ruud, ‌runner-up to Carlos Alcaraz in the ‌2022 final, will be replaced in the ‌draw by lucky loser Arthur Gea, who takes on Juan Manuel Cerundolo in ‌the opening round.

The 27-year-old Ruud had ⁠retired during ‌the second set of his Cincinnati Open ​meeting with Christopher O'Connell earlier this month and said he had ​not recovered in time.

"Unfortunately, my back hasn't healed as quickly as we had ⁠hoped," Ruud ​said on Instagram.

"We've been optimistic that I would recover in time, but my team and I have decided that we ‌need to think long term and give my body the time it needs. I'm very sad to announce that I have to withdraw from this year's US Open singles event.

"It's never easy to miss a Grand Slam, but I know this is the ‌right decision. I'll take the time ​I need to recover properly and ‌come back stronger."

Ruud competed in the revamped mixed doubles tournament last week, partnering Diana Shnaider and the pair were beaten in the quarter-finals by ⁠Andrey Rublev and ⁠Mirra Andreeva.