Rory McIlroy, the esteemed golfer who was among the most outspoken opponents of his sport’s swelling ties to Saudi Arabia, has resigned from the PGA Tour’s board.

The tour confirmed his departure in a statement on Tuesday night.

“Given the extraordinary time and effort that Rory — and all of his fellow player directors — have invested in the tour during this unprecedented, transformational period in our history, we certainly understand and respect his decision to step down in order to focus on his game and his family,” Commissioner Jay Monahan and Edward D. Herlihy, the board’s chairman, said in the statement.

Mr. McIlroy, the men said, was “instrumental in helping shape the success of the tour, and his willingness to thoughtfully voice his opinions has been especially impactful.”

Mr. McIlroy’s agent did not respond to a message seeking comment.

The decision by Mr. McIlroy came about five months after the tour, following secret negotiations, struck an agreement with Saudi Arabia’s sovereign wealth fund to try to create a joint company that would end golf’s money-fueled war for supremacy. Most board members, including Mr. McIlroy, had no knowledge of the agreement or the talks that led to it until shortly before it was announced in June and upended the duel between the tour and LIV Golf, the league Saudi Arabia built with a blend of billions of dollars and marquee defections from the PGA Tour.

Mr. McIlroy soon expressed a pragmatic fatalism about the agreement — which calls for the tour and the wealth fund to combine their commercial golf businesses — and the proposed partnership with Saudi Arabia, which has been expanding its investments in sports.

“If you’re thinking about one of the biggest sovereign wealth funds in the world, would you rather have them as a partner or an enemy?” Mr. McIlroy asked on June 7, the day after the tour announced the transaction, which has still not closed. “At the end of the day, money talks, and you would rather have them as a partner.”

But he also made no secret that the tour’s machinations had blindsided and stung him. Few golfers had been more strident critics of LIV and the players who joined it, and the PGA Tour had benefited from the credibility of a four-time major tournament winner’s serving, in effect, as its leading public champion.

“It’s hard for me to not sit up here and feel somewhat like a sacrificial lamb and feeling like I’ve put myself out there and this is what happens,” Mr. McIlroy, who was also among the tour’s leaders during the pandemic, said at the same news conference in Toronto.

Although he soldiered on, he signaled this week that he had tired of the role. Asked in the United Arab Emirates whether he was enjoying his board tenure, Mr. McIlroy replied: “Not particularly, no. Not what I signed up for whenever I went on the board. But yeah, the game of professional golf has been in flux for the last two years.”

He gave no hint that an exit was in the offing.

On Monday, the 12-member board finished a meeting at the tour’s headquarters in Ponte Vedra Beach, Fla., where it heard about a handful of bids for minority stakes that could usurp or come alongside any money from the Saudis. In a memo to players on Tuesday, Mr. Monahan, the tour’s commissioner, said the board had “agreed to continue the negotiation process in order to select the final minority investor(s) in a timely manner.”

Mr. Monahan said in his memo that the tour had heard from “dozens” of prospects about potential investments and winnowed the candidates to a smaller group for board review. For the tour, which has faced blowback from Congress and the Justice Department over its evolving approach to working with Saudi Arabia, there are stakes beyond money.

Some players and executives believe that a role for influential American investors could diminish Washington’s criticism of — and possible efforts to block — the transaction.

“Even if a deal does get done, it’s not a sure thing,” Mr. McIlroy said this week. “So yeah, we are just going to have to wait and see. But in my opinion, the faster something gets done, the better.”

Mr. McIlroy is the second person to resign from the tour’s board since the summer. In July, Randall Stephenson, the former AT&T chief executive, quit the seat he had occupied for a dozen years, citing his “serious concerns with how this framework agreement came to fruition without board oversight.” At the time, Mr. Stephenson wrote that he could not “objectively evaluate or in good conscience support” the agreement, especially given the conclusion of U.S. intelligence services that Saudi Arabia was responsible for the murder of the dissident journalist Jamal Khashoggi in 2018.

Mr. Stephenson’s departure turned heads on Wall Street and in golf’s inner sanctums. But the decision by Mr. McIlroy is a particularly public blow to the tour and its board. Although the group still includes figures like Tiger Woods and Patrick Cantlay, Mr. McIlroy, 34, has long been one of golf’s most amiable stars.

When the time came, though, for the tour to engage in negotiations with the wealth fund, he was among the board members left out of the talks.

Only two members, Mr. Herlihy, a partner at the Wall Street law firm Wachtell, Lipton, Rosen & Katz, and James J. Dunne III, vice chairman of the investment bank Piper Sandler, were involved. The secrecy infuriated other board members and helped stir a player uprising that led to the summertime installation of Mr. Woods as a director.

Hours before the tour acknowledged Mr. McIlroy’s resignation, it announced a replacement for Mr. Stephenson, Joseph W. Gorder, the executive chairman of Valero’s board.