CNN  — 

Four-time major winner Brooks Koepka has pulled out of next week’s US Open because of injury.

Koepka called an end to his PGA Tour season after failing to make the cut at the Wyndham Championship in August but reportedly had planned to take part in the US Open, which starts September 17 at Winged Foot Golf Club in New York.

However, due to persistent knee and hip injuries, he has forced to withdraw from the major, which he won in 2017 and 2018.

“Unfortunately, I have decided to withdraw from next week’s US Open,” the 30-year-old said on Twitter. “I’m looking forward to getting healthy and competing at 100% again very soon.”

Having begun the year as the world No.1, knee and hip injuries this season have curtailed Koepka’s success on the golf course, meaning he has slipped to world No.8.

Koepka’s injury woes began after suffering a partially torn patellar tendon in his left knee last year, for which he underwent a stem cell procedure.

He further aggravated it just two tournaments later when he slipped on wet concrete, forcing him to retire from the 2019 CJ Cup. He missed three months of golf as a result.

Since returning to action in February, Koepka has finished in the top 10 just twice, with his highest finish coming at the World Golf Championships-FedEx St. Jude Invitational in August, where he finished tied in second place.

As well as winning the US Open twice, Koepka has won the PGA Championship twice, in 2018 and 2019.

Koepka recieves treatment on the 12th hole during the second round of the 2020 PGA Championship.

In his search for a historic PGA Championship three-peat last month, Koepka had a promising opening three rounds, sitting just two shots off the lead before fading on the final day. But even during the major, he required treatment from a medical assistant.

“It’s not the knee,” Koepka said when he missed the cut at the Wyndham Championship. “This is physical. I know how to do it, I can do it, I just physically can’t do it.

“My golf swing is fine. If I can physically do it, then yes, everything’s fine.”

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The 120th US Open will be conducted without spectators on site due to the coronavirus pandemic. The major was originally scheduled to be played between June 18 to 21 but was postponed to this month.