Experience on the PGA Tour can be expensive. For Michael Brennan, the bill arrived this week in the form of a disqualification.

And a lesson he won’t soon forget.

Brennan, a 23-year-old rookie who won in his first PGA Tour start last fall, was disqualified following the first round of the Farmers Insurance Open at Torrey Pines after officials determined he had used non-permitted green-reading materials. He had opened with a two-under 70 on the North Course and stood tied for 55th at the time.

The Tour’s initial statement offered little detail beyond citing a violation of Model Local Rule G-11. On Friday, Brennan provided the missing context himself.

In an Instagram post, Brennan said he had recently begun working with a course data analyst to sharpen his course strategy. The analyst provided green maps with hole locations to assist with approach planning, and Brennan said he sketched a few arrows into his yardage book while studying those materials—an action prohibited under Tour rules.

After completing his round, Brennan said he asked the analyst for clarification on a feature shown on the maps and was then informed that transferring such information into a yardage book was not allowed. Upon realizing the mistake, Brennan said he contacted a PGA Tour rules official and was subsequently disqualified.

Model Local Rule G-11 restricts the use of course-mapping features and handwritten notes that could assist with reading the line of play on the putting green, part of a broader effort to limit the role of detailed green-reading aids in competition.

Brennan vaulted to national attention in October when he won the Bank of Utah Championship at Black Desert Resort after being granted a sponsor’s exemption into the event. The victory earned him a two-year PGA Tour exemption, and the right to an education at the highest level of the game. Brennan kicked off the 2026 calendar with a missed cut at the Sony Open in Hawaii, followed by a 56th-place finish at the American Express in La Quinta last week. With every start, he gets more seasoning, not all of it pleasant. But Brennan appeared to be taking it all in stride.

“While this has been a painful lesson to learn,” Brennan wrote, “I am looking forward to the party in the desert next week at the Waste Management Phoenix Open.”

Actually, the official name of the event is the WM Phoenix Open. But we won’t disqualify him for that.

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