Rory McIlroy annoyed over driver disclosure at US PGA Championship

• Masters champion's driver failed test at Quail Hollow

• The process is supposed to be kept confidential'

Rory McIlroy has admitted being pissed off" and annoyed" after news of a forced driver change leaked during the US PGA Championship last month. McIlroy had to switch heads early in the week at Quail Hollow after his driver was deemed non-conforming by a United States Golf Association test.

The scenario is perfectly common - when club faces become too springy through overuse - and also happened to the eventual champion Scottie Scheffler. The process, though, is meant to be private.