SAN DIEGO – There’s more at stake this week than just a U.S. Open trophy.

This is the final week for players to qualify for the Tokyo Olympics, which begin in late July. The top 60 players as determined by the Olympic Golf Rankings (which are reflective of the Official World Golf Ranking) are eligible to play at Kasumigaseki Country Club in Japan.

Each country can have up to four players per squad, provided they are within the top 15 of the ranking. Otherwise, a country will have a maximum of two players.

The qualifying deadline is June 21, the day after the U.S. Open at Torrey Pines.

Here’s a look at the most hotly contested races:

UNITED STATES

Justin Thomas is the only current lock on the U.S. team. As of now, Collin Morikawa (4), Bryson DeChambeau (5) and Xander Schauffele (6) would round out the rest of the American side. Though we’re still awaiting the world-ranking projection for the U.S. Open, there should be plenty of volatility, with Patrick Cantlay (7), Patrick Reed (8), Brooks Koepka (10), Webb Simpson (12) and Tony Finau (14) among those who could make the team with a strong performance at Torrey Pines. World No. 1 Dustin Johnson previously said he would not compete in the Olympics.

GREAT BRITAIN AND IRELAND

Tyrrell Hatton, at No. 9 in the rankings, appears safe on the GB&I side, but the rest of the group is undecided. Paul Casey (19) is currently in line to make the team, but only one ranking spot behind is Matt Fitzpatrick (20). Tommy Fleetwood (33) and Justin Rose (42) need huge weeks at Torrey. Lee Westwood has already announced that he was removing himself from consideration.

AUSTRALIA

Cameron Smith (28) appears in good shape to be in Tokyo, but Marc Leishman (45) will be trying to hold off Matt Jones (60) for the other team spot. Adam Scott will once again skip the Games while Jason Day, at No. 69, did not qualify for the U.S. Open and won’t be able to improve his standing.

SOUTH AFRICA

Louis Oosthuizen has locked up his spot, but Garrick Higgo’s breakout year has shaken up the rest of the squad. With his victory at the Palmetto Championship, the 21-year-old is now 39^th in the rankings, leapfrogging Christiaan Bezuidenhout (46). Branden Grace (71) is also on the outside looking in.

As of June 14, here is what the Olympic field would look like, barring any further withdrawals:

Justin Thomas

Jon Rahm

Collin Morikawa

Bryson DeChambeau

Xander Schauffele

Tyrrell Hatton

Rory McIlroy

Viktor Hovland

Hideki Matsuyama

Louis Oosthuizen

Paul Casey

Abraham Ancer

Sungjae Im

Cameron Smith

Joaquin Niemann

Victor Perez

Corey Conners

Garrick Higgo

Shane Lowry

Marc Leishman

Si Woo Kim

Sergio Garcia

Carlos Ortiz

Sebastian Munoz

Mackenzie Hughes

Emiliano Grillo

Antoine Rozner

Rikuya Hoshino

Thomas Detry

Alex Noren

Guido Migliozzi

Martin Kaymer

Thomas Pieters

Rasmus Hojgaard

Sami Valimaki

Matthias Schwab

Kalle Samooja

Jazz Janewattananond

Henrik Norlander

Jhonattan Vegas

Mito Pereira

Joachim B Hansen

Rory Sabbatini

Sepp Straka

Francesco Molinari

Ryan Fox

Joost Luiten

C.T. Pan

Adrian Meronk

Maximilian Kieffer

Juvic Pagunsan

Wil Besseling

Ondrej Lieser

Scott Vincent

Gunn Charoenkul

Fabrizio Zanotti

Gavin Green

Carl Yuan

Rafael Campos

Kristian K Johannessen