SOUTHAMPTON, N.Y. -- Jessica Korda turned to her boyfriend and said, "Johnny, grab the bag, let's go."

The 20-year-old American fired her caddie midway through the third round of the U.S. Women's Open, and Johnny DelPrete instantaneously went from spectator to participant.

Korda said she and Jason Gilroyed had several disagreements over the first nine holes Saturday.

Jessica Korda fired her caddie mid-round during the U.S. Women's Open, putting her boyfriend to work in order to finish out the round. Scott Halleran/Getty Images

"It's a U.S. Open. It's a big week for me," she said after the round. "It's one of the most important weeks for me of the year. I was just not in the right state of mind."

The switch seemed to work: After shooting 5 over on the front nine, Korda was 1 under the rest of the way. She finished with a 76 and was tied for sixth at 1 over, 11 strokes behind leader Inbee Park.

"The first few holes I was very shaky, but my boyfriend/caddie kept me very calm out there and kept it very light," Korda said. "And it was kind of funny seeing him fumble over yardage."

DelPrete is a professional golfer, playing on the Web.com Tour in 2012, but never had caddied for Korda. He'll be back on the bag for Sunday's final round.

Her father, 1998 Australian Open tennis champ Petr Korda, is the caddie for younger daughter, Nelly, this week. He caddied for Jessica when she was an amateur, but she said she wouldn't even consider asking him to switch from one child to the other Sunday. Nelly, the youngest player in the tournament at 14, was tied for 61st at 13 over.

Gilroyed has caddied for Korda for about a year. Asked if they had issues before Saturday, she said, "I think everybody has problems every week."

She's not sure what will happen after Sunday, but DelPrete isn't a long-term option.

Korda never had fired a caddie mid-round before, or seen a playing partner do it -- though she'd heard stories of it happening.

"I care about Jason a lot. He is a great guy," she said. "That's just how it happens sometimes in life. That was one of those things today that it just unfolded. It was very hard for me to do. I'm not that type of person to take these things really easily."