Norway's Viktor Hovland was forced to withdraw during the final round of the Travelers Championship in Cromwell, Connecticut, on Sunday due to a neck injury.
Hovland, 27, appeared to be in pain on his opening tee shot in the final round, though he made par on the first hole.
He bogeyed the second hole before exiting the course at TPC River Highlands.
The seven-time PGA Tour winner shot a 7-under 63 on Saturday and entered Sunday in the running for a top-10 finish in the PGA Tour's final signature event of the year.
Hovland, who is ninth in the Official World Golf Ranking, opened with a 4-under 66 then followed it up with a 5-over 75 before rebounding on Saturday.
Hovland finished third at the US Open last week and has four top-25 finishes in his last six starts.
He will attempt to recuperate in time to compete in The Open in four weeks.
Hovland was not the only player to withdraw on Sunday. Eric Cole exited due to illness before the final round.
Cole, 37, carded a 68, 67 and 69 to shoot at 6-under-par 204 to reside tied for 14th place after three rounds.