If you know anything about LPGA star Lydia Ko, “nervous” is not an adjective you’d likely use to describe her.

The former World No. 1 (and current No. 3) has put together the kind of career record that can only be accomplished by someone with ice running through her veins.

That stellar record includes a whopping 22 LPGA Tour wins, three major titles and a complete set of Olympic medals. And none of this is new — she’s being doing amazing things on the golf course since she was a literal kid (she captured her first LPGA win at 15 years old).

It’s hard to imagine how a player like that could get nervous in competition. Her playing partner at this week’s Grant Thornton Invitational, Jason Day, could hardly believe it himself when Ko addressed the serious nerves she faced in her debut at the mixed PGA Tour-LPGA Tour event last year.

“I don’t understand how you’re nervous,” Day, who was her teammate last year as well, said during their joint press conference Thursday at Tiburon Golf Club.

But it turns out greats like Ko can get nervous, and she was very much so in the early goings of the 2023 Grant Thornton last December. So nervous, that she lost control of her tee shots, and even duffed one, at least as she sees it.

“It was actually quite embarrassing because honestly I don’t think I hit a single fairway on the front nine and I remember duffing a driver,” Ko explained on Thursday. “I was like oh, man, I feel so bad he has to play with me. It’s like there’s no choice, right?”

Why? For one, playing alongside PGA Tour pros took some adjustments.

“As much as it is familiar, it’s different. I haven’t had that much experience playing with other like male Tour pros and especially somebody that I’ve looked up to and seen on TV for a really long time,” Ko said of teaming up with Day last year.

But she added that Day did everything he could to make her comfortable, saying, “Jason was great. He asked me questions about what I was working on in my game and we were talking about pitching and all that.”

Fortunately for Ko, the nerves seemed to wear off halfway through the first round.

“It was a very new experience, but by Friday, mid-Friday I think I was able to get rid of the nerves and focus on what I was doing,” she said. “But our whole team with our caddies, we just had a great dynamic and just a good time out there and I think that just helped with, you know, just not thinking about the results and we were getting more excited and just pumping each other up. At the end I think that was one of the biggest things on why we were able to have such success last year.”