CHARLOTTE, N.C. — Scottie Scheffler, after he won the PGA Championship on Sunday, revealed that his regular driver was randomly tested by the USGA on Tuesday and was deemed nonconforming, same as Rory McIlroy’s. That left Scheffler to use his backup driver during the tournament. “The driver testing is something that regularly happens on tour, and my driver did fail me this week,’’ he said. “We had a feeling that it was going to [fail] coming in because I’ve used that driver for over a year.’’ McIlroy, who refused to speak to reporters after all four of his rounds this week, was believed to be angered that a report surfaced Friday about his driver being nonconforming. “I would argue that if we’re going to test the drivers, we need to be even more robust in the way we test them,’’ Scheffler said. “If it’s something we’re going to take seriously, I feel like we’re almost going halfway with it right now. “If we’re going to test only a third of the field … if we’re going to do it right, leave it up to us as players, like the rest of the rules in the game of golf are. It’s a newer rule that we haven’t quite gotten right yet. I think we have some stuff to figure out. If we’re going to do it, we might as well do it right, get even more strict.’’