Rory McIlroy withdrew ahead of his third round on Saturday at the Arnold Palmer Invitational due to a back injury.
Austin Smotherman pulled out during his round, also with a back injury, at the Bay Hil Club & Lodge in Orlando, Florida.
World No 2 McIlroy of Northern Ireland was 4-under through two rounds at the PGA Tour's signature event, nine shots behind 36-hole leader Daniel Berger.
McIlroy, 36, was playing his third PGA Tour event of the season. The five-time major winner finished T14 at Pebble Beach and T2 at The Genesis Invitational last month.
Smotherman bogeyed three of the first five holes Saturday before leaving the course.
Smotherman, 31, opened with a 2-over 74 on Thursday before carding a 1-under 71 on Friday.
He was the runner-up last week at the Cognizant Classic for his second top-10 finish of the 2026 season.
Smotherman has four professional wins, three on the Korn Ferry Tour and one on the PGA Tour Latinoamerica.