PORTRUSH, Northern Ireland — After a 6-under-par 65 at Royal Portrush, Xander Schauffele revealed that he was battling an early week surprise: a failed driver test necessitating an effort to find a replacement.

When asked after his round what the difference was between his opening 74 and Friday’s 6-under-par round, Schauffele admirably admitted he was struggling with finding the right driver specs.

“I had some equipment issues earlier with the R&A and what not,” Schauffele said.

Asked to elaborate, the Callaway staffer said, “They tested my driver. Yeah, and it didn’t pass.”

The R&A randomly tested 30 drivers at Royal Portrush and while there were rumors of other clubs not passing the Coefficient of Restitution test used by all tours and governing bodies, the R&A refused to comment on if Schauffele was the only one with a hot driver.

“It barely missed,” Schauffele said of the 9 degree Callaway Epic Flash Sub Zero that he put into play just before winning January’s Sentry Tournament of Champions.

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“I had a bit of a run-in with the R&A, which wasn’t the most fun,” Schauffele said, though his beef was over the number of players tested and not with the rule or testing procedure.

“I thought it was a little bit unfair — I would gladly give up my driver if it’s not conforming,” he said after moving to -3 and just five out of the British Open lead. “But there’s still 130 other players in the field that potentially have a non-conforming driver, as well. Had a word with them and hopefully they’ll take my comments seriously and my concern.”

The R&A is standing by the procedures, according to a spokesman.

“We believe that 30 is a reasonable sample and a practical option for conducting this process in the week of a major championship.”

The spokesman added, “We randomly selected 30 players for driver testing as we did at last year’s Championship and we can confirm the statement that Xander’s driver failed. We have worked with Xander and his manufacturer to ensure that he has a number of conforming drivers he can use this week.”

The test is designed to prevent more than an 83 percent transfer of energy between clubhead and ball. Any more is a “spring-like effect” with the current COR limit set in 1998 for metal woods at 0.822 with a test tolerance of .008. So any driver exceeding 0.830 fails, even if the effect is accentuated by wear and tear on the clubface.

Turned it around today @TheOpen. 🦅 Let's keep it going on Moving Day. pic.twitter.com/RMbjonHfAk — Xander Schauffele (@XSchauffele) July 19, 2019

Schauffele took full responsibility for the failed test and even took a compliment from writers acknowledging his calmness.

“I got the most agitated when I talked to my dad,” he said. “But it is what it is, you know. I have a legal driver now and I sort of put that one to rest and happy to see that the driver performing like it did today, so that was very comforting.”