Finau was running backwards in an enthusiastic celebration of a hole-in-one on the seventh when his left ankle buckled underneath him.
The 28-year-old then popped the dislocated ankle back into place and carried on, but declined to speak to reporters after leaving the ninth green.
X-rays later showed it was not broken, with Finau now waiting on the results of an MRI scan before deciding whether to go ahead with the tournament.
On Twitter, he said: "Crazy day. Thanks for thoughts of concern, messages and prayers from all. I'm optimistic."
