Phil Mickelson famously changed from Titleist to Callaway clubs shortly before the 2004 Ryder Cup at Oakland Hills, lost twice on the opening day in partnership with Tiger Woods and won just one point from four matches as Europe stormed to a record nine-point win.

But McIlroy revealed on Wednesday that he had been practising with the club for months and was all too aware of Mickelson’s struggles a decade ago.

”Phil Mickelson nearly hit me off the first tee in 2004,” said McIlroy, who was in Detroit as a spectator after helping Europe win the junior Ryder Cup in Ohio.

”I was standing down the left-hand side, so I’m very aware of what he did that week.

”Hey look, Phil changed from one equipment manufacturer to another. This is a driver that I’ve actually been using and practising with since June. I wouldn’t be putting it in the bag if I didn’t feel it was better.

”I think everyone saw yesterday it was the only driver I had out there in the bag. It’s looking likely that it’s going to be in the bag this week.”

European captain Paul McGinley said he was unconcerned by the news, adding: “I trust Rory with his decisions. He spoke to me and said first thing when he got here, ’I’ve been testing something new, this is where I’m at with it, do you have any problem?’

“I said, ’Rory, I don’t have any problem. You make your own decisions. You have your own team around you. You are the best player in the world, you make your own decisions and I’m not going to influence that.’

“I’d never dream of giving a player a lesson or telling them what to do. They make their own decisions, they’re top players and that’s why they are here.”