LONDON • Jack Nicklaus has warned Rory McIlroy that getting married could reduce his chances of reclaiming his place as the world's leading golfer, and that he will have to decide what matters most to him if he is to become the greatest to play the game.

McIlroy, who is set to marry Erica Stoll next year, will end 2016 as the world No. 2 but unable to add to his fourth Major title, which he claimed in 2014.

Nicklaus, who won a record 18 Major titles, said that McIlroy is already one of the game's greats but that he must improve to become the greatest. The American fears that marriage may distract from the 27-year-old from his game.

"When you are young and single and just one-dimensional, you pretty much can do things at your leisure," Nicklaus told the BBC.

"Once you start getting married, having a family, other business interests, then you've got to learn how to manage your time and use it efficiently. He'll learn that.

"He has to work hard, he's got to focus on what he is trying to do and it is up to him.

"Certainly he has all the tools to be able to do it - it is just whether he has the desire and the willingness to give up some other things. And that's his call.

"I mean, whatever Rory does, he has established himself as one of the great players that have played the game.

"Whether he wants to be the greatest player to have played the game, that's his determination and it's his decision whether he wants to make that effort to try to do that."

This year, McIlroy picked up the Tour Championship and FedExCup as well as the Deutsche Bank Championship.

The Masters is the only Major that has eluded him and he returns to Augusta for the third time to challenge for it again in April.

Nicklaus believes that McIlroy can still win it.

"He certainly has the type of game that would do well at Augusta and he has done well before - he just hasn't finished it," said the 76-year-old golf legend.

"The media are going to focus on this because he hasn't won it. He'll win it. He's a good player."

THE TIMES, LONDON