Jake Knapp withdrew prior to Thursday’s first round at the Cadillac Championship with a left thumb strain.
Norway’s Kristoffer Reitan replaced him in the field at Trump National Doral’s Blue Monster Course in Miami.
Knapp, 31, currently ranks No. 36 in the world and 13th in the PGA Tour’s FedEx Cup standings.
Knapp has finished inside the top 11 in seven of his nine events this season. The outlier was a T74 at the RBC Heritage earlier this month after he placed 11th at the Masters.
