PGA Championship 2025: Rory McIlroy's driver deemed non-conforming by USGA ahead of Quail Hollow

CHARLOTTE — Rory McIlroy had to switch drivers ahead of the first round of the PGA Championship after his gamer was deemed non-conforming, according to a report by SiriusXM PGA Tour Radio.

McIlroy is known as the best driver of the golf ball of his generation. At the start of the week, he ranked first for the season on the PGA Tour in strokes gained/off the tee and third in driving distance. However, he struggled during Thursday’s opening round at Quail Hollow, finding just four fairways en route to posting a three-over 74. McIlroy did not speak to the media after the round, instead heading to the range to work on his game.

According to the report, the USGA deemed McIlroy’s driver non-conforming on Tuesday. McIlroy plays a TaylorMade Qi10 driver. Earlier on Friday, Golf Digest sent a request for comment to McIlroy’s representatives about whether McIlroy’s driver had failed compliance, but no correspondence was returned.

The USGA and R&A are often brought into tournaments to randomly test drivers for their compliance, performing what's known as a CT (Characteristic Time) test. A USGA spokesperson confirmed the USGA did testing at the PGA Championship at the request of the PGA of America. "That program is consistent with the same level of support that we provice to the PGA Tour as part of their regular program for driver testing," the USGA said in an email to Golf Digest. It's unclear how many players had their drivers tested. Testing drivers ahead of a major championship is a regular practice.

Test results are not released to the public and kept within tight groups. The most notable incident came at the 2019 Open Championship, when Xander Schauffele told the media after his Friday round that his driver was taken earlier that week. Schauffele sounded off about what he perceived to be an unfair process.

"I would gladly give up my driver if it's not conforming. But there's still 130 other players in the field that potentially have a nonconforming driver as well," Schauffele said. "Had a word with [the R&A], and hopefully they take my comments seriously and my concern just because it wasn't my plan to show up Monday morning of a major or Tuesday—sorry, it was Tuesday evening where I was doing driver testing here. It's not really what players want to be doing.

"What's the fair thing to do? Just test the whole field. It's plain and simple. When I talked to them, they didn't really know how to ... you can't really answer that question. You test everyone, it's simple as that.”

That's a valid point, and it would hardly be a difficult practice to employ, albeit inconvenient momentarily, as a CT test might take minutes. (The CT test measures "characteristic time," a reference to the flexibility of a driver face. The CT limit is 239 microseconds, with a tolerance that extends to 257 microseconds. For all practical purpose, that range is within the noise of its ultimate effect on driver ball speeds. It also basically reflects a generous wiggle room in the testing tolerance.) But while the CT limits are clear, it's also true that a driver can be conforming one week and fall into a non-conforming state the next week through general use. Additionally, a driver could be tested by a manufacturer and read as conforming and then be tested by the USGA and read as nonconforming. That all depends on how precisely the manufacturer's CT machine is calibrated in line with the USGA's. Not difficult to do, but easy to overlook.

Also, because of the way drivers are designed today, there is a growing problem with what's called "CT creep." Basically, that means through use, particularly by high-speed players (like McIlroy), the face can become more flexible (even on a composite face, like McIlroy's TaylorMade Qi10). That would take a driver that measured as conforming originally to eventually register in the CT test as over the limit. That change could take hundreds of hits, could take a dozen or might just be one; it depends on how close to the limit the driver was in the first place. Most manufacturers routinely test players drivers to alert them that their driver might be getting close to the limit. But the difference between a conforming driver and a non-conforming driver, particularly in this instance, is probably a foot or two at most. Not yards.

McIlroy did not speak to the media again after his second round on Friday, having shot a two-under 69 to make the cut on the number at one-over 143. During his play on Friday, McIlroy hit six out of 14 fairways, leaving him last among the 74 players who made the cut in strokes gained/off the tee. On his final hole Friday, Quail Hollow's difficult par-4 18th, McIlroy pulled his driver left, his ball hitting the roof of a grandstand and then landing on the bank of a river that runs down the left side of the hole. He eventually made bogey, which was good enough to be playing on the week. He is scheduled to tee off on Saturday morning in the third round at 8:25 a.m. along with Xander Schuaffele.

The news comes a month after McIlroy, 35, completed the career Grand Slam by capturing the Masters in a playoff over Justin Rose. McIlroy has also won the Players Championship and AT&T Pebble Beach Pro-Am.

Golf Digest senior writer Joel Beall’s debut book, Playing Dirty: Rediscovering Golf's Soul in Scotland in an Age of Sportswashing and Civil War, is on sale now at BackNinePress and all major bookstores.

—Additional reporting from Mike Stachura