Nick Faldo says he was right to question Rory McIlroy's switch to Nike clubs when it was first announced.
When Faldo heard that the Northern Irishman was going to change his equipment back in October he immediately questioned the decision, and nothing he's seen from McIlroy since has changed his opinion.
"You can't mess with that at such a young age," he said at the time.
Now, Faldo adds: "Rory very simply messed with a winning formula. He went from rookie of the year to world No. 1 and has been through a lot and thought he could start again.
"As I said from Day 1, I tweeted right away when it was announced that this was a dangerous move. People said, 'Oh, he's so talented, he can adapt.' Well, why should the world No. 1 be adapting to something new? As we discovered six months later, he's busy still trying putters, still trying drivers. It's not as easy."
Faldo reckons the change has severely dented McIlroy's confidence, and hopes the former world number one hasn't done irreparable damage to his game.
"We get a millisecond of feel at impact and if it's going great, it builds confidence; if it's suddenly something different to what you've been doing or thinking you're going to do, that hurts your confidence," said Faldo. "So I hope he hasn't gone too far, but it's damaged his confidence."