Scottie confirms driver was flagged, joins Xander in calling for testing change

Driver testing has been a hot topic at the PGA Championship following a report that the USGA deemed Rory McIlroy's driver nonconforming in the buildup to Round 1 at Quail Hollow.

McIlroy, who declined to speak to the media after all four rounds, struggled off the tee using his backup, hitting less than 50% of the fairways over 72 holes.

While the buzz has surrounded McIlroy, Xander Schauffele suggested after Sunday's final round that the Irishman wasn't the only one to fail, pointing at tournament leader Scottie Scheffler as well.

"I think Scott is winning the tournament, and I think he switched to his backup, too," Schauffele told Adam Schupak of Golf Week.

Schauffele, whose driver was ruled nonconforming ahead of the 2019 Open Championship, expressed frustration Sunday with the testing process, raising concerns that only one-third of the field gets tested.

"I think they should test everyone's driver," Schauffele said. "It's not right to just test 50 guys. It just doesn't make sense if you're in it for the spirit (of the game). The whole point of it is to protect the integrity of the field. If you don't test everyone across the board, I don't think you're protecting the whole field."

Scheffler confirmed after his five-stroke win that his driver was indeed flagged earlier in the week, forcing him to use his backup en route to victory. He joined Schauffele in calling for change to the testing process during his press conference alongside the Wanamaker Trophy.

"My driver did fail me this week. We had a feeling that it was going to be coming because I've used that driver for over a year. I was kind of fortunate for it to last that long, I felt like," Scheffler said, according to ASAP Sports. "It's a newer rule that we haven't quite gotten right yet. I think we have some stuff to figure out. I think, if we're going to do it, we might as well do it right, get more robust and get even more strict. You can test guys every week, if you want. I mean, there's no reason why we shouldn't."

The USGA and PGA of America don't disclose the results of driver testing, leaving a significant amount of secrecy around the process. While a failed test may reflect poorly on a player, it's rarely a case of anything intentional.

The most common cause for a failed test is a driver that's been used so often that the face has gotten too thin.