The biggest threat to Rory McIlroy underlines his weakness at The Masters

Rory McIlroy headed for the range after squandering a six-shot lead in the third round of the Masters (Matt Slocum/AP) - (AP)

The relationship between six-time Masters winner Jack Nicklaus and defending Masters champion Rory McIlroy is close enough that, earlier this week, just before Nicklaus took his tee shot as the honorary starter, the 86-year-old felt fit to dispense some advice to the Ulsterman on how to join the very select group of golfers to defend their title at Augusta.

“No f***ing double bogeys.”