Jake Knapp withdrew before the start of Thursday's opening round at the Arnold Palmer Invitational in Orlando, Fla.
He was replaced by China's Haotong Li in the field at the PGA Tour signature event at Bay Hill Club and Lodge.
Knapp, 31, is ranked No 41 in the world and No 7 in the FedEx Cup standings after a strong start to the season.
After opening with a T11 at the Sony Open, Knapp has posted four consecutive top-10 finishes.
Knapp collected his lone PGA Tour win to date at the Mexico Open in 2024.
Li, 30, is ranked No 71 in the world and is a four-time winner on the European Tour.