Well, that’s a surprise. Jon Rahm, the top-ranked player expected to be in the field for this week’s American Express, withdrew Monday, citing no reason. Tuesday his manager said Rahm had tweaked something while practicing. Rahm, the winner here in 2018, is on a streak of three straight top-10 finishes going back to October’s Zozo. His absence means Patrick Cantlay, seventh in the Hawley Ratings; Patrick Reed, 10th; and Brooks Koepka, 12th, are the highest-ranked players in the field for this event.

It never was the case that this event. played in the desert about 145 miles inland from the Pacific coast, was a reliable spot for favorites. Within just the last eight years the event winners have included the famous (Rahm; Bill Haas, ranked 16th when he won in 2015) and the not-so-famous (Adam Long, ranked 655th when he won in 2019; Andrew Landry (ranked 229th when he won last year).

Cantlay comes in playing his normal steady game. He won the Zozo in October and was in the top 20 at the Masters and Champions in his two appearances since then. He was in the top 10 in 2018, his only recent appearance here, and missed the cut as a 20-year-old in 2013.

Reed, who picked up his second Tour victory here in 2014, is in or around the top 10 almost all the time. In 11 appearances over the last six months, he has seven top-10s, including thirds on the Euro Tour at Dubai in December and the BMW PGA in October. He’s not a particularly good fit for these courses, although obviously he overcame that issue in the win a few years ago. He skipped the event the last two years after a missed cut in 2018.

Koepka is here for the first time and making his first appearance of 2021. He was in the top 10 at both the Masters and at Houston last fall before missing the cut at Mayakoba in his last time out.

In the first three rounds, each player will play one round on each of the three courses used in this event. That’s the PGA West Stadium course, the PGA West Nicklaus Tournament course, and the La Quinta Country Club, all minutes apart in this golf-course-rich area. After a cut following the third round, the final round will be at the Stadium course, noted for its set of difficult par-3s.

In terms of the PGA Tour set of individual statistics, driving distance and greens in regulation have correlated most closely with success on the varying set of courses used over the past eight years. Paul Casey and Scottie Scheffler are the best fits for the course among the higher-ranked players. Both are in the top quarter of all U.S./ Euro pros in both driving and GIRs. Others in the field who could benefit most significantly from course fit include Martin Laird (top 5 percent in GIR), Emiliano Grillo (also top 5 percent in GIR), Aaron Wise (ditto), John Huh (top 2 percent in GIR), and Will Gordon (top 10 percent in driving and top quarter in GIR).

The field includes a number of mid-range players who are coming in with things on the upswing. They include:

• Patton Kizzire has two top-10s and an 11th in four outings going back to November. He was seventh last week. He has not cracked the top 40 in visits to La Quinta the last five years.
• Huh was in the top 20 in three out of four fall appearances going back to the Shriners. He’s among the leaders in GIR and has one top-10 in six appearances here.
• Wise was the runner-up at Mayakoba and just missed the top 10 at Houston last fall. He also missed the cut here the last two years.
• Chris Kirk was the runner-up last week in the Sony, rescuing his career after a self-described fight with alcoholism.