Hideki Matsuyama felt unwell and left a pro-am event on Wednesday but expects to take part in Thursday's first round at the Northern Trust Open.
Matsuyama, who won his second U.S. tour title at the Phoenix Open on Feb. 7, stopped play after nine holes at the Riviera Country Club. He canceled his official news conference and used the afternoon for recovery.
"There's no fever and I have a good appetite. I'd like to take a proper rest," Matsuyama said before leaving the course.
Hiroshi Iwata will be looking for another good tournament after finishing fourth last week at the AT&T Pebble Beach Pro-Am, but Ryo Ishikawa will be absent for the tournament and also next week's Honda Classic with lower-back pain.
Ishikawa's management company said he is not eligible to play in the Cadillac Championship in the World Golf Championships starting March 3, while no decision has been made about the Valspar Championship from March 11.
"I'll play in a tournament once I feel OK taking a full swing," Ishikawa said on his official website.