The American Express has the largest field of the PGA Tour season, with 156 players beginning the California tournament on Thursday.
However, at the halfway stage of the event, which features a cut after 54 holes, three had withdrawn.
The first to go was Luke Clanton, who managed a two-under round of 70 on Thursday before withdrawing due to illness ahead of his second round.
For Clanton, it adds to a frustrating start to the season, having missed the cut in his first tournament, the Sony Open in Hawaii.
The former World No.1 amateur will be hoping to recover in time for his next scheduled start at the Farmers Insurance Open, which begins on 29th January.
Rico Hoey persevered a little longer. After a five-over 77 on Thursday, he played the front nine of his second round, going one over, before also succumbing to illness.
Like Clanton, Hoey began his season at the Sony Open in Hawaii, finishing T50, and he is also expected to tee it up at next week’s Torrey Pines event, illness permitting.
Nick Dunlap went into the tournament hoping to replicate his success in 2023, when he became the first amateur to win a PGA Tour event since Phil Mickelson in 1991.
Dunlap has since won on the PGA Tour as a professional, when he lifted the Barracuda Championship trophy later that year, but he won’t be adding to that tally with a second win at The American Express after withdrawing following the second round.
Dunlap was five over after a 77 in his first round at the Pete Dye Stadium Course, before improving on Friday with a 74 at La Quinta Country Club, but that was his last action at the event, with an undisclosed injury bringing an end to his challenge after 36 holes.
The 22-year-old, who began his season with a tie for 61st at the Sony Open in Hawaii, is not in the Farmers Insurance Open field.
At the halfway stage of the tournament, Scottie Scheffler and Blades Brown led the way at 17 under. For Brown, there's a chance to make history, because if he makes the cut, he'll become the first player to play eight rounds in consecutive days across the Korn Ferry Tour and the PGA Tour.
