Golf legend Jack Nicklaus has rapped Rory McIlroy across the knuckles – and told the Irishman he shouldn’t have walked off the course at the Honda Classic last Friday.

The American hero then backed McIlroy to prove himself at the Masters at Augusta next month after a wisdom tooth problem allegedly forced him out after just eight holes of his second round in Florida.

Nicklaus, who regularly hosts and advises McIlroy at his Bear Club, spoke openly and candidly about the young Ulsterman’s current problems.

The 18-time major winner addressed reporters after he attended the final day’s play at the Honda Classic in Palm Beach Gardens.

Nicklaus revealed to reporters that he has yet to speak to McIlroy since the incident but had spoken to him last Monday.

The Daily Telegraph newspaper reports that while Nicklaus was keen to point out that he was not sure of the reasons for McIlroy pulling out after eight holes of his second round, his comments left little room for doubt concerning his feelings.

Nicklaus said: “He shouldn’t have walked off the golf course.

“That was unfortunate. I think if he’d thought about it for five minutes he wouldn’t have done it. I just think he was just so frustrated with how he’s been playing the last month or so it just got to him.

“That would be my assessment, although I may be talking out of school.”

Set to address the media at a Tuesday press conference at the WGC Cadillac Championship in Miami, McIlroy spent the weekend practising at the Bear Club with coach Michael Bannon.

He is expected to apologise for his walk-off when he appears at the Tuesday media briefing.

US TV pundit Johnnie Miller, himself a two-time major champion, claimed that McIlroy’s playing partners Ernie Els and Mark Wilson had urged him not to withdraw on Friday.

The NBC analyst said: “I know the guys he was playing with told him ‘don’t walk off, you really don’t know the mess you’re causing.’”

Meanwhile, Nicklaus has also refuted claims that McIlroy is suffering since switching clubs from Titleist to Nike in a $250million deal.

The Golden Bear added: “I saw Rory on Monday and we had a discussion.

“He told me he was struggling with his irons. I told him, ‘Don’t worry about your clubs; you’re too good and talented. And if you need to get something done about your clubs I’m sure Nike will do something.’

“But by the time The Masters comes around I’m sure Rory will be fine. He just has to move on.”

Jack Nicklaus (Right) has slammed Rory McIlroy walking off course at the Honda Classic last FridayReuters