Donald sustained the problem on the last round of the US Open
A wrist injury has forced Luke Donald to withdraw from the Open at Royal Birkdale on 17 July.
The Englishman has not played since he damaged his wrist in the final round of the US Open in June, pulling out of the Scottish Open on Monday.
"It is extremely disappointing to not be able to be at Royal Birkdale," said Donald, who said he may undergo surgery if his injury does not heal properly.
"But the important thing is for me to focus on what's best for my health."
Donald has slipped down the Ryder Cup standings since sustaining the injury during the final round of the US Open at Torrey Pines.
The world number 19 was in joint 23rd place after 14 holes of the final round at the US Open, won memorably by Tiger Woods in a play-off the following day, when he had his left wrist strapped by medics and elected not to continue.
"I first felt a 'pop' in my wrist on the 15th tee during the final round of the US Open, and over the past three weeks I have been meeting with hand specialists to determine the best course of treatment for the injury," said Donald.
The 30-year-old has since been diagnosed with a subluxation of the Extensor Carpi Ulnaris (ECU) tendon in his left wrist.
"The fact that it is a Ryder Cup year is also frustrating, but you can't account for injuries," added Donald.
"My preference is to try and do everything I can to rehabilitate the injury naturally and leave surgery as the last resort.
"After consulting a number of hand specialists, I plan on following a prescribed rehabilitation schedule for the next three to four weeks as they are optimistic about the chances to heal the injury without surgery.
"But if surgery is deemed necessary, I have been assured that it is a fairly common procedure with a high success rate."
American Jerry Kelly will take Donald's place at the Open.
The Scottish Open has been successful for Donald in recent seasons - he finished fourth last year and was joint runner-up to Johan Edfors two years ago.