While traveling to Johannesburg for his home country's Joburg Open, he sustained a weird injury in an airport that later prompted him to withdraw from the event.
"The body feels great but I had a different incident this week with jamming my fingers in trolleys at the airport", Oosthuizen said at his Wednesday press conference.
He finished in a share of 16th in last week's AfrAsia Bank Mauritius Open in hot, humid, windy conditions, so the persistent rain in the lead-up to the Joburg Open has had him remembering his February victory.
"I didn't want to tee off and then have to withdraw after one hole, and take someone else's spot", said Oosthuizen, who would have been one of the favourites to win this week. "I just can't do that".
"I'm probably going to go do an X-ray today", Oosthuizen added.
"I am not anxious too much about length because that's not much of an issue on either course", he said. "I hope I didn't crack the middle finger there somehow but it's swollen quite a bit and it's right on that pressure point where you hold your grip".
"I was really looking forward to playing and trying to get back inside the world top 20 before the end of the year".
In a major change for the Joburg Open 2018, the Asian Tour has been added as the third sanctioning tour to endorse the Joburg Open along with longstanding PGA's the Sunshine Tour and European Tour.
Cody Martin of the U.S. has been drafted into Oosthuizen's three-ball, which also includes last week's victor in Mauritius, Frittelli, and Jazz Janewattananond of Thailand.