No reason was given for Duval dropping out of the event.

The major marked the 20th anniversary of Duval's only major title, the 2001 Open Championship at Royal Lytham & St Annes.

Duval had told a US publication last week that he planned to play this year's Open Championship at Royal St George's starting on July 15.

John Catlin, an American who only plays on the European Tour, replaced Duval in the field.

American Adam Long became the new first alternate.

Earlier Matsuyama, who tested positive for COVID-19 after the first round of the Rocket Mortgage Classic on July 2, confirmed he wouldn't travel due to United Kingdom health protocols.

"While I am vaccinated and have passed the required pre-travel COVID test, not enough time has passed for me to comfortably join the charter flight and risk exposure to the other players and personnel on board." – Bubba Watson

The reigning Masters champ has remained quarantined and hasn't shown symptoms but continues to test positive.

"I'm feeling fine but haven't been able to practice in preparation for The Open," Matsuyama said.

"Combining that with the difficult travel to the UK, my team and I have decided it's best to withdraw to ensure everyone's safety."

Matsuyama will focus on the Tokyo Olympics, which begins its golf competition on July 29.

Watson, a two-time Masters winner, withdrew after having direct contact with someone who tested positive.

"While I am vaccinated and have passed the required pre-travel COVID test, not enough time has passed for me to comfortably join the charter flight and risk exposure to the other players and personnel on board," explained Watson.

They'll be replaced in the field with Americans Harold Varner III and Brendan Steele.