The PGA Tour’s landmark agreement with LIV Golf cast a shadow over the U.S. Open at the Los Angeles Country Club and Phil Mickelson, who joined the Saudi-backed series last year, was an apparent target of some heckling on Thursday.

The fan was on the railing of the grandstand at the 18th hole and was heckling "Lefty" for more than 30 seconds, according to Sports Illustrated. The topics of the badgering were Mickelson’s deal with LIV Golf and an alleged sponsorship with Victoria’s Secret.

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Golf Magazine’s Dylan Dethier took a photo of the alleged heckler, who was wearing a sombrero.

The incident caused Mickelson to briefly lose focus but he finished up his round with a 69 and tied for 25th. Xander Schauffele and Rickie Fowler finished with a first-round 62 and set a record for the lowest score for a U.S. Open round in the tournament’s history.

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"I played OK. I hit a few swings coming down the stretch, I made two bad swings that cost me a few strokes," Mickelson said, via Yahoo Sports. "But I hit a lot of good shots today. It’s a decent start, and I have a chance tomorrow morning to come out and shoot a good, solid round to get myself in position for the weekend."

As far as the LIV Golf deal goes, Mickelson said he didn’t want to talk about it just yet.

"I don’t want to detract right now from this tournament and where I’m at," he added. "I’m playing well, I want to get myself in contention."