World No. 1 Scottie Scheffler, who won at Augusta National earlier this year for his second green jacket, is back after the birth of his first child. Rory McIlroy, winner at the Valhalla at the 2014 PGA Championship, has won two events in a row entering the week: the Zurich Classic of New Orleans and the Wells Fargo Championship.

As the PGA Championship makes a fourth turn at an humongous Valhalla course with a past both brief and storybook, much of the talk has been about bureaucracy.

A look back at the trending topics in golf the last time the PGA Championship was held at Valhalla in 2014: Tiger Woods nearly a no-show Tiger Woods had the first of what would be four back surgeries early that year and had played only three times since April.