Rory McIlroy described winning The Open Championship at St Andrews as "the holy grail" of golf.

The 150th edition of the sport's oldest major is taking place at the home of golf this week, with McIlroy eyeing a second Claret Jug after his triumph in 2014.

McIlroy was unable to defend his title the following year – the last time it was staged at the Old Course – after suffering a knee injury while playing football.

And the Northern Irishman acknowledged that winning this landmark event at the most famous course in the world would represent an extra special achievement.

On Monday, Jack Nicklaus recalled Bobby Jones' remark that "a golfer's resume is not complete unless he's won at St Andrews", a notion that was put to McIlroy, who replied: "I don't know if a golfer's career isn't complete if you don't, but I think it's the holy grail of our sport.

"Not a lot of people are going to get that opportunity to achieve that, but that's what winning an Open at St Andrews is. It's one of the highest achievements that you can have in golf.

"There's a lot of great players that have won Opens and maybe not won Opens at St Andrews, so I think it's unfair to say that a golfer's career isn't complete without that.

"But it's certainly up there with one of the greatest things you can do in our game."

McIlroy still just needs a Masters win to complete the sweep of golf's majors and was asked if a green jacket was at this stage more desirable than prevailing at St Andrews, but he was quick to point out it did not have to be one or the other.

"I guess it's both," he said. "Obviously I'd love to win both. And I'll be greedy and say that I'll take both."