The R&A remain hopeful of staging both The 149th Open and the AIG Women's British Open on schedule, although they are "examining a range of scenarios".
The winner of the Latin America Amateur Championship this week will receive a spot in The Open for the first time.
Marcus Armitage birdied the final hole of the South African Open to join Branden Grace and Jaco Ahlers in the field for The 149th Open.
The R&A has announced record-breaking demand for tickets for The 149th Open at Royal St George's next year.
James Sugrue secured an invite to three of the next four majors by claiming a one-hole win in a dramatic final at the 124th Amateur Championship.
Darren Clarke is relishing The Open returning to Royal St George's in 2020, the venue where he won his only major.
The R&A has announced that the 2020 Open will be played at Royal St George's, the scene of Darren Clarke's memorable victory in 2011.