Rickie Fowler withdrew from the WM Phoenix Open before Friday's second round due to illness, the PGA Tour said.
He shot a 3-over 74 on Thursday in Round 1 at TPC Scottsdale.
Fowler, 36, has six career wins, including the 2019 WM Phoenix Open. He also was the runner-up in 2010 and 2016.
He was scheduled to play with Billy Horschel and Sahith Theegala on Thursday. They now will play as a twosome.
Wyndham Clark shot a 7-under 64 on Thursday to take the Round 1 lead.