Michael Thorbjornsen got his PGA Tour season started a week later than expected due to a painful illness.

The 23-year-old Stanford product, who earned his PGA Tour by finishing No. 1 in the 2024 PGA Tour University standings, was originally in the field for last week’s Sony Open in Hawaii. However, Thorbjornsen withdrew at the last minute.

“Yeah, last week I had tonsillitis,” Thorbjornsen told reporters Thursday after shooting a seven-under-par 65 in the first round of the American Express. “The day I arrived is kind of when it hit me, and I was stuck in bed for three days straight. It was really, really bad. Yeah, obviously kind of past that now, got some good reps, came out here, I think, Saturday, so got an extra day of practice, and kind of got things back in order.

“I think Tuesday was the worst day,” Thorbjornsen said. “Those three days feel like one day, but we were thinking, OK, if I sleep really well, if I feel good enough, even if, I mean, it’s not completely healed, if I can just manage to scrounge out maybe one-, two-under, I’ll feel even better for the next day and have a later tee time. Unfortunately, I didn’t sleep great, woke up in the morning, and didn’t feel any better, so that’s kind of when we decided to withdraw.”

Thorbjornsen withdrew from the Sony Open at Waialae Country Club at 5:50 a.m. local time on Thursday before the tournament got underway. Canadian Nick Taylor went on to win the event by defeating Nico Echavarria in a playoff.

The good news for Thorbjornsen is that the antibiotics “did the trick,” and he didn’t need to have his tonsils removed.

The Stanford product followed up his first-round 65 at La Quinta Country Club with a 4-under-par 68 at the Nicklaus Tournament Course.

Thorbjornsen is still looking for his first career PGA Tour win. He has three career top-10 finishes, including a runner-up at last year’s John Deere classic.

A breakthrough feels like it’s on the horizon for Thorbjornsen. His body and swing are in a good place, and his tonsils are cooperating.

“My tonsils aren’t touching each other anymore, which is good,” Thorbjornsen said. “Yeah, everything feels good, no complaints.”